Got, it, tks!
Installation is carried out in reverse order. Tighten the receiver screws to a torque of 7 Nm (62 in-lbs) in metallic trigger guards and max. 5Nm (44 in-lbs) in plastic trigger guards. Make sure to put metallic recoil block (B) in place into stock and pull barreled receiver backwards before tightening the receiver screws in order to remove the slack from the recoil lug.