well...first, remove the screws and see if you can gently pry it up. You might be surprised. If not, use a 5200 remover and soak the area (it will degrade any 5200 that it comes in contact with - so keep this in mind). Let that soak a while and remove the parts. The blade under the edge might give it some incentive and might help work the remover into the joint a little if it is problematic.

Reseal it with Sikaflex UV.