Place your MK1 MOD 2-M stripped lower in a vice.
Install a standard mag release/catch in your lower until the mag catch screw is flush with the mag release button. Do not over tighten.
Apply pressure to the mag release button, and slip the proprietary left side mag release paddle underneath the standard mag catch bar.
Release pressure from the mag release button. Using a drop of blue Loctite on the threads, insert one of the included bolt catch screws and tighten until flush. Work the left side mag release paddle in by pressing it down and letting it release a few times. Your MK1 MOD 2-M stripped lower has a recessed area where the bolt release lever will go. Place the included bolt catch spring in the small circular recession, with the bolt release lever over it ensuring the spring stays put. Using a drop of blue Loctite on the threads, insert the other included bolt catch screw to retain the bolt release lever. Put the bolt catch spring from the lower parts kit into the hole for it, then insert the provided longer bolt release through pin instead of the bolt catch plunger from the lower parts kit. Install the standard bolt catch with the roll pin, both from the lower parts kit.
The tension screw is to be installed after the takedown pin has been installed, but before the pistol grip is installed. With the takedown pin pushed into place, install the tension pin from the bottom of the lower in the hole furthest back where the pistol grip covers. The correct hole is straight up and down; the angled hole is for the pistol grip screw.
Turn the tension screw clockwise until the white tip almost touches the bottom of the takedown pin.
To see the PDF instructions for this, please click here.