Try hitting the inside of the panel, to try and jolt the bog so it comes off in slabs... If you have enough room for a hammer or large drift punch, that is!
I wouldn't be doin this,u may stuff your panel before the bog lifts off.bog sticks pretty good unless put on by a amature.I have had 1 door totally covered with kilo's of bog on my first 1600 (previous owner was T boned from a jaguar ).Now i have seen this door get t boned by a kid on a bike and another occasion some random guy come out of no where and kick the same door in again.after both times, the door kicked back out straight with no cracking of the bog .You will knock highs into the panels before it falls of .
The tent idea sounds like the go or try some type of dust extracting unit.try taping the vacum cleaner hose to the grinder