I looked up some instructions online. Here is a good one.
Now is my experiment with a dollar bill
TA-DA!
My puzzle is how to fix the ring. Now I am using the adhesive tape as the instruction said, but the tape makes the ring so not cool. If anyone has a good idea of how to fix the ring, please tell me.
Reference:
1. one dollar bill ring (I think it's for kids and men, ugly)