my passenger window fell inside the door tonight. how do I fix it?
Are there any tips/tricks to this? How do I remove the inner door trim panel?

 

Looks like you are going to need a window regulator, there are plastic pieces that fail (break) that allows the window to drop.

There is a write up w/pics in the "How To's" here, but I believe that it is a post face lift MY. Should be helpful.

 

i just tried fixing this exact problem with mine just now and now the car wont start anymore!

the panel just pulls out, its secured with pops along the edges, hidden from view. once youve pulled them out all round, the grip handle in the door has a little rubber mat at the bottom, covering two screws. remove those and then the only thing holding all that in is a couple of electrical connectors and the actual door opening handle and lock, which is a fiddly thing, but if you pull those levers open as far as they go, the panel, along with the black plastic cowl around the levers, all pulls away.

then the problem with my window was a couple or plastic parts, 1 brown and 1 white, which had snapped in some way, and then the cable attached to the motor ended up getting all tangled up.

 

Some people have replaced the plastic parts, most replace the regulator, the motor can be re-used.

Here's some info from Gus's site JagRepair.com - Jaguar Repair Information Resource