I thought I would give detailed instructions for anyone trying to replace the trigger group on any large/supermag frame DW: Remove allen screw from right rear of frame, replace mainspring and guide, replace hammer and pin in place, turn frame over with mainspring base up, insert allen screw into grip screw hole, cock hammer and hold in place while tightening allen screw(just finger tight) mainspring is now trapped, unpin hammer and remove. reinvert frame with trigger slot up and muzzle slightly up, place front of trigger group in slot and engage front retainer notch, lower group until it rests on rear notch, while holding group in place turn over and insert a small flat screwdriver into the hammer slot and lift the transfer bar until it touches the the front hammer slot (you may have to lower the trigger group slightly to allow the bar to slide forward) once in place it will stay as long as the trigger group is held in place, turn over and snap in rear of trigger group by pushing down and depressing the catch with an allen wrench or small punch, try trigger to insure hand is in slot and transfer bar is in forward slot, turn over and place in trigger, lower with hammer against firing pin slot(you may have to remove the rear sight, I didn't), move hammer to rear and you may have to pull the trigger some to align the hole for the pin, when pinned; remove allen screw from mainspring base and replace on frame, try trigger single and double action, if all ok, replace grip and you're done.