[Gamesy]

oh damn.... so you cant bring in any tools at all? not even hand tools?
if you can my suggestion would be a small hacksaw and a big ass prybar, the good thing is that the flexplate on our cars are abuot 3/16" thick so it wont be an issue with not getting the thing to bend, try seeing if you can possibly cut the bolts or the flexplate metal around the bolt and try prying it off.
Chances are its an older flexplate so you might get lucky and have the thing snap on you .

Another thing might be to try and break the bolts that mount the plate to the engine but they are closer together so it would be more of a challenge.