there is CA debonder, sold at most hobby shops..

Might be just as simple to take a SHARP X-acto knife and cut it free. (or a razor saw...) You'll probably need to buy a piece of wood at the local hobby shop (or hobby lobby) to replace what you cut off. (about $1 to $1.50 and you will have a LOT left over.)

The problem is not super serious... you could also take wood and fill the bottom and then reshape the top. It will work just fine.

The small section of wood between the ailerons is not critical. Most of it is over the fuselage... and what you have done would just leave a gap under the trailing edge when you rubber band the wing on. Eventually the rubber bands would snap this raised part off. (and that's really the worst effect it will have)

the ailerons being in the correct postion would look a little funny (drooped vs that misaligned piece...) but the thing would fly just fine.

My choice would be to just fill the inderside to be level with the bottom of the wing ribs, then sand down the top.