Step 2: Cut Hole in Top of Hat for Disco Ball
First detach the disco ball from the "motor part" that spins the ball (it should pop right off).
You'll see the "motor part" is circular, and will have a slightly indented smaller circular portion at the top. You will want to cut a hole in the top of the hat just slightly smaller than this "top circle."
If you cut the hole the right size you'll be able to pop the "top circle" through the top of the hat and it will fit snug enough to hold the entire "motor part" up.