Blimey that's a situation :o

The only thing I can think of suggesting is if you have After Effects then try using the Difference Matte to remove anything in the background.

You would need a still frame of the background without the actors, but I don't know if this is possible to get from your footage.

Also because it's in the woods it may not work brilliant because of any movement in the trees and the leaves. It may not even work at all but it would be worth a shot.

The Difference Matte, put simply, removes the still frame source from the targeted footage so anything that is the same is erased / transparent.

Other than this I can't think of another way of doing it besides frame by frame removal.