Butt pad you need a med philips screw driver with a round shaft, put a bit of lube on the shaft and slide it right on in..... you can leave the screws in the pad if you back it out a bit, then switch to the other screw and back it out a bit, repeat this until the pad comes off without removing the screws from the pad.
Once the pad is off you will need a long and large flat head screw driver typically for the stock bolt.