Out of the three pieces there will be a front with happy birthday on it.

Glue the center piece (the piece that looks like a “u”? to the backside of the front piece with the open side facing up.

Last, glue the back (solid piece) to the backside. This will leave a gap in the middle to slide the money into the middle. 

I took a piece of polycarbonate sheet to fit in the groove the keep the $ from falling out. Just cut it a hair bigger than the dollar on all sides and it will fit great. I also made this stand that you can get all over xtool projects.