First you need the gun.
Then you need a saw.
Hot glue gun and duct tape.
The black thing on the back of the recon cs6 and the nerf raider.
Now for the kind of difficult part .Take hot glue and glue the black piece onto the back of the gun.The first time i used duct tape. but it isnt good looking
Your finshed then go out there and whip some butts.