@ItBeMe welded a driver to my stripped out screw. I was going to have to replace the screw anyway.
While I was there I had him install a new security system for my truck.
Drop ins are easy. Take off the pistol grip since you'll likely need to remove the safety to install the drop in. Watch where the little pin and spring go that retains the safety selector.
I recommend anti-walk pins too for modular drop in triggers.
Save yourself some aggravation and order an extra power hammer spring for the FCG. Also, if you plan on shooting suppressed or with a variety of ammo, I'd spend a few extra shekels and buy a Riflespeed adjustable gasblock.
Not only can I troll threads, I can use a torque wrench to tighten a castle nut, smart enough to know I have no business telling a man what he should charge for his time and I'm rich enough to own three torque tools.