Ok your first mistake was the you glued the canopy using model glue instead of canopy glue. canopy glue can come off very easy without damaging the paint.
this is what you should've done
1. coat the canopy w/ liquid masking ( let dry )
2. glue the canopy with canopy glue
3.) paint the model, you can spray over the canopy cuz you've mask'd it
4.) remove the canopy when the paint is dry, peel off the masking
5) add decals to canopy then dip in future
6.) glue back on w/ canopy glue
right now I would just try to use a exacto knive and carfully cut it out
clean the canopy up and redip it in future should bring back the shine