First there is a mirror in the top I removed the one from this box, but if you put camo on your face you might want to leave it in. Just take the liner out of the bottom and put it in the top. Here it is before removal
Then reach in with a flat screw driver and gently lift and it will come out in one piece.
Then take the bottom cover out and place it in the top where the mirror was. Next take a piece of 1 by 8 and cut it down to fit in the bottom of the box. I like a tight fit so I cut it 1/16" smaller than the inside of the box. Then mark the center both ways with a light pencil mark, go 3/4" both ways to make you first center lines and space all the cross hair on 1 1/2" centers for broadhead locations.