i got some 3 dot sights off ebay for my springer cut a grove in a peice of nylon & staked the front sight on with A FLAT NOSED then a round nosed punch, the sights shipped from alaska .
pull down on button ar lower rear part of receiver , slide rear cover forward & up , the carrier & bolt will come to the rear to be lifted out, trigger assy comes out by removing big screw at back of trigger guard