1) Remove factory basepad and retainer plate.
2)
Remove magazine spring and slide factory follower down to base of
magazine so that the load assist pin can be removed from the follower. NOTE: YOU WILL NOT USE THE METAL PIN WITH THE BLUE FOLLOWER
3) Remove factory follower.
4) Insert HiCap follower into the magazine body.
5) Insert magazine spring into magazine body.
6)
Compress spring into magazine body and slide on the aluminum basepad.
Assure that the spring is in the pocket of the basepad.
7) Finger tighten set screw with the included hex wrench.
Mag upgrade 
