how do you move a clam once it attaches?

[fresh]

Just as the title says...

I have a clam that has attached to a piece of rock that is almost impossible to move, yet I would like to move the location of the clam!

The reason I want this done is because there is a rock covered with GSP that is right next to the clam and is touching/covering the clam.

I also wanted to know how harmful are the GSP's to clams?

Thanks