[Dickie]

The challenge might be to get a nice crisp edge between the painted surface and the tweeter.
You could investigate what type of glue is used. Test some of the dribbles on the back to see if they are flexible and will peel off the surface. Or is it dry and solid and will only come off in scraping. Glue removers tend to be solvents of one form or another so you would have to try a few to see if any one softened the glue but not the panel! It may be possible to slowly go round the joint with a sharp blade and gradually ease things apart. But the back plate looks fairly flimsy and might distort with too much abuse. Also its not clear how the tweeter leadouts connect to the tags so you need to be especially careful around them.