These 3d printed ferrules install similarly to traditional ferrules with one key exception: we advise against using force to slide the ferrule up the shaft.  3d printed plastic is not as flexible as traditional ferrules.  And 3d printed ferrules with intricate designs are a bit more delicate where 2 colors meet and form a seam.  Using force to push a ferrule that is too snug higher up a shaft can cause cracking or splitting.  Instead, if a ferrule is too snug for your shaft, we recommend boring out the inner diameter of the ferrule with a cylindrical file, a drill, or sandpaper until it can slide up to where it will sit above the hosel.