Each gun is a little different. If you cannot determine which bolts to remove, contact B-square directly.

Typically, you would remove the pin/bolt (it may be a panhead bolt---with a flathead screw slot) directly above the trigger assembly. The second B-square bolt may or may not go through your receiver. On my Ithaca, the second mounting pin actually goes below the receiver in front of the trigger, and stays secure via upward pressure.

If you can posts digital pics of each we can talk you through it easily...