Instructions: Cut the notches in the front, dont cut everything down to the barrel, sand the cut area until it fits. Sand the 3 little bumps where the mod connects with the gun in the back on both sides.
The file with the cln at the end is without text, the other one has a nice message for everybody looking at your gun.
I used a pressure fit, no glue needed but feel free to attach it how ever you want.
Scratching it makes it look nicer, files work amazing for that.