Unless you have a graco or similar device on the gun, there are two screws holding the buttplate on. You may have to work at it a bit to find the tiny slots in the pad-- they can be very well hidden in plain site 
Use a little lubricant on the screwdriver-- it will keep a dried out pad from shedding rubber and looking lousy if you decide to put it back on.
Use a little lubricant on the screwdriver-- it will keep a dried out pad from shedding rubber and looking lousy if you decide to put it back on.