Sure, within the backstrap is a large pin that runs up the back strap that twists to lock and unlock. Its not the easiest thing to unlock it either as its a tight fit. Once you rotate the base of the pin it pulls out. Then you can pull the backstrap off. The backstraps are very snug, nothing loose feeling. They come with the medium size installed and the majority of people leave it that way. If you are satisfied with the grip of the Glock 17 then you would likly end up in the Medium camp. I prefer the small. Try them out sometime, while Glock tops my list the M&P is second.