You will need to separate the interlock on the siding and place a piece of wood behind the siding and then re-do the interlock. Possibly 1/2 inch plywood will work. Even better would be a piece of bevel siding. The piece only needs to be a bit bigger than the mounting plate.
There are tools available to help with breaking the interlock and re-connecting the pieces.
There are tools available to help with breaking the interlock and re-connecting the pieces.