When I replaced my bowsprit I used Debond, a heat gun, some metal bladed putty knives, and some small plastic timber wedges.
Warm the joint with a heat gun, then spray some Debond on and let it sit awhile. Then use the metal blade putty knife to start breaking the joint. It may take a few passes around because you will be exposing "new" bonded sealant as you make your way deeper under the pad. Tap the plastic timber wedges into the joint as you go around and leave them in. They will provide constant pressure to break the seal.
I did this and got my bowsprit up with only a very small patch of gel coat coming up from the surface right in the middle of the project area. I admit that was my fault, I got a little excited as I saw the results.
It's not that hard and cheap to do if you are handy.
Here is the Debond link, this stuff is crucial:
Debond Marine Formula