Hmm, can't really think of any other way to flatten that bow out without removing. But first of all, does it snap pretty hard passing thru center and more importantly, can you leave it at neutral, or does it snap to slightly up or down elevator. See where I'm going with this? If you can’t leave it at neutral (level flight) and it keeps wanting to snap up or down, you’re going to have one heck of a flying experience….can we say roller coaster?

Secondly, if I remember correctly, that plane came with CA hinges. Personally, I’d cut the elevator out; strip the covering off, toss in a zip lock and soak in some water. Remove from bag, place between two flat boards, clamp or weigh down, and let thoroughly dry. This ‘should’ take the bow out, but takes to much time. OR spend a few bucks and get a new elevator from LHS.

As for the hinges, trim the old ones and sand flush. Now create new hinge slots, as close to the originals as possible and reattached H-Stab.