How do I get this screwed back on? Mossberg930

[Munny$hot]

@DogSac, I would use a C clamp with a piece of wood on the top of the gas housing, insert the spring, collar with 2 pieces of steel with grease in between the steel pieces. With enough pressure on the C clamp turn the collar "Counter clockwise" with a steel rod in the notched cut out of the collar until the collar's threads mates/drops into place with the gas chamber threads, tighten the C clamp a little more while turning the collar "Clock wise". When you have enough threads started remove the C clamp etc and tighten until the collar is seated.