fender repacement (rubber epoxy removal?)

[ted_brah]

i removed a damaged driver side front panel today and to my surprise, there's a rubber epoxy/glue (thick under coating). i had a hell of a time getting it free from the chassis, but in the process i thrashed the panel (lucky it's already dented and thrashed). i'm gonna remove a perfect replacement panel off a parts car, but want to remove it without warping or bending it. is there an easy way to do this? a chemical i can apply to eat or break down the under coating?

thanks for you time!