Maybe a different gun is in order for very close range? Or dial the power selector back a bit...should be able to shoot as little 5 yds with it set at 1 using brown. I have a power selector chart but haven't figured out how to post pics in here yet lol
All that holds that on is an allen wrench screw. You will also need the bebe and the spring that falls out when you take off the power selector. If you have your book for your gun you will see what I am taking about. You can get all that at your local hard wear. I would take the power selector with you so they can match up the screw.