it takes 5 min to do if you drill and pin it.
keep in mind the law (don't ask for chapter and verse here) states the bbl must be 16" min. if you install a device to bring it to this legal length . the addition must be installed so as to be unable to be removed with hand tools. drill a small hole in through one of the flats (preferably the bottom one) while it is installed and clocked to the correct position. then drill a little more ,to dimple the bbl. use a tension pin. like the ones use for bolt release. tap down into hider and make sure when seated you cannot unscrew without damaging the threads. if it is secure mix a little jb weld fill in the hole it's considered permanent, and legal. or swing by and i'll throw a quick mig weld on it. i use that heat paste from brownells to keep the temp down. all you need is a quick spark and its on for good. you can hold the muzzle end in your hand right afterwards and it's barely warm.