How to replace the battery in a Palm Tungsten T3

Be careful using other online directions, because some are not clear about what they call different directions or different parts, or are just plain wrong.

Terminology

I will call the screen side the "front" and the opposite the "back".
I will call the lower back piece with the serial number on it is the "back panel".
I will call the docking-connector end the "bottom" and the power-switch end the "top".
I will call the part with the docking connector on it the "bottom panel."

Disassembly

Remove the stylus and any memory card, and set them aside.
Remove the 4 tiny screws from the side of the back panel (if they haven't fallen out naturally). You'll need a very tiny Phillips screwdriver for this. Or you can use the very tip of the smaller blade on most Swiss Army knives.
Look in the middle at the very bottom end of the back panel. Right below the "palm" in "www.palm.com" you can see that a metal tabs sticks down from the back panel into the part underneath, and then bends toward the bottom end of the T3. This is known as "the secret catch." It hooks under the bottom panel and holds it on, while simlutaneously being very hard to see. This information alone makes this page worth every cent you're paying for it.
Slide the T3 open the normal way.
Take something thin (the same knife blade works well), and push gently down in the crack between the back panel and bottom panel, to push that tab down. While doing this, jiggle the bottom panel and it should come loose. Move it down just a little bit, but do not take it off.
Now the back panel is free at its bottom end, but still held by two clips near the top end, that run in little tracks when you slide the T3 open or closed. At the top end of the back panel there are two large rectangular holes, and two tiny round holes.
Lift the bottom end of the back panel slightly, then take a paper clip and push it gently into one of the tiny holes to release a catch. When it releases you should be able to pull down that side of the back panel slightly. Then do the same thing with the other tiny hole. Go back and forth a few times, and the back panel will come free. It has no wires or anything attached, so just take it off and set it aside.
Now you can see a flat cable that connects the bottom panel to the main body. Gently pull or pry around the sides and you can unplug its end from the main body.
That cable is also glued down; very slowly and evenly pull it and the glue should release. This is not the time to rush or lose patience.
Once the cable is unglued, you can slide the bottom panel off (with the cable still attached to it), and set it aside.
Now remove the two screws at the bottom end of the main body. They go into a small metal bar on the front, which will fall free when you remove the second screw. Set all these aside.
Look around the edges, and notice the line where the back of what's left separates (call this part the "upper back panel" to keep it straight from the "back panel" you removed earlier).
Right above where the case narrows at the sides (that is, the point where the slide stops when you close the case in normal use), the upper back panel has very tiny tabs bent inward, that catch into the plastic underneath. One or both of these may be holding the upper back panel down. If so, take something thin and set it flat against the slide track on that side; slide it up until the tip is under the corner of the upper back panel, and gently pry the upper back panel out to the side just enough to come loose.
Once both sides are loose, find and remove two screws at the top edge of the upper back panel.
Once those 2 screws are out, just down from there find 2 more catches on the sides. Again using a fine blade of some kind, pop those loose. BUT do not lift the back yet. It is still attached by the battery cable, which plugs in right next to the cable from the bottom panel that you removed earlier.
Work the battery cable loose, and then lift off the upper back panel.
If you lifted off the upper back panel too soon, you may have lifted the motherboard out by accident too. Carefully replace it, lining up the button side first, and then jiggling to get the other side to set down too. The hard part is getting the hole at the top right of the motherboard to fit over the plastic posts where those last two long screws came from.
Turn the upper back panel over, and you will find the battery. Unfortunately for the present job, it's glued in. Slip that trusty blade in and slowly work the battery loose.

Inventory

You should now have 8 little screws and one loose little bar, and should still know which ones came from where. The longest screws are the ones you just took out; the 4 smallest are the ones you took out first.
Hopefully, you also have a replacement battery.

Battery replacement and reassembly

Insert your new battery. You can use double-sided tape or perhaps a little rubber cement to hold it down. You could leave it unfastened, but I'd bet on it rattling around, which could detract from how much you impress your friends with your technical skill.
Plug the battery wire in, and make sure any extra wire is out of the way so it won't get pinched when you replace the upper back panel.
To replace the upper back panel, first catch the main power switch so the front part of it ends up inside the case, not outside. Then put the panel down into place, and pinch the sides to seat all four catches (remember them?).
Then put in the two (longest) screws at the top of the upper back panel. Don't tighten them too hard: they're only threaded into plastic, and this isn't their first time, either.
At this point you can check your work by turning the T3 on with the main power switch, and then off again. Don't try to do much, since the battery probably has little charge (or perhaps none, in which case this test will fail even if you did everything right), and since you don't have the buttons connected yet.
Line up that little loose metal bar; it fits fairly obviously just below the screen. Get its screws back in.
Slide the bottom panel into its tracks, making sure it moves smoothly. Plug the cable back in, *then* glue or tape it down. That way it will already be aligned. If you do it in the other order, it won't be.
Pick up the back panel, and look on the inside side. You'll see two clips just above the paper-clip holes you used earlier. You need to get those back into the tracks in the back of the upper back panel, by slipping them in at the bottom end of the tracks. This requires a little fiddling, but isn't too hard. If, like mine, your back panel was dented, you can flatten it by placing it on a hard, flat, clean surface, and gently hammering it back out (hammering is best done before reinstalling the back panel). Do not hit the clips or the sides, or you'll regret trying this.
Once the back panel is in the grooves and moving smoothly, you need to get the secret catch hooked back in, under the back of the docking connector. Push down slightly on the back panel, and at the same time push the bottom panel in, hooking it over the catch.
Finally, replace those 4 #80-size screws on the sides. If needed, you can order replacements here.

Congratulations!

gethightech.com -- This site is pretty good overall, but neglects to say which "panel" is involved at crucial times, and doesn't mention those 5 catches.