BE SURE TO GET A LONG ALLEN KEY IF YOU DON'T ALREADY HAVE ONE.
Installation and adjustment procedure
***BE SURE THE FIREARM IS UNLOADED BEFORE PROCEEDING***
To install the adjuster remove the upper receiver from the lower receiver to make things easier. Cock the hammer back and set the safety lever to safe. THE LOWER MUST BE ON "SAFE" TO ADJUST CORRECTLY. On the adjuster, remove the set screw all the way. Apply Loctite to the set screw and reinstall the way it came out (with hex head going back into grip screw) and run the set screw all the way in. Remove original grip screw making sure not to lose the safety spring and detent under the grip. Install adjuster into grip and tighten down completely using a 3/16" allen. Then tighten the set screw using a 2mm or 5/64” allen wrench until it stops (not tight). At this point the safety lever won't move or will be hard to move, leave it on safe. Back the set screw out 1/8 turn at a time until the safety lever moves freely again. Function test the lower to ensure the hammer and trigger are engaging and releasing properly and that the safety is functioning correctly. If the hammer remains held back by the disconnector after releasing the trigger, you must loosen the set screw more until it releases the hammer. Let the loctite dry overnight. This is as far as you can adjust the adjuster without modifying the trigger group to allow further adjustment.