I made a video about this wallet on Youtube! This is a slightly modified version just because I wanted it to be simpler.
Check it out here: https://www.youtube.com/watch?v=eWJQ7LQ6HPU&lc=z23hjp3bhkyfw3gcbacdp43blykrv53lgq05sn1arnpw03c010c
All you have to do is print 1 of each piece (1 w/ cirlcle and 1 plain), or it works well with just 2 plain panels as well.
I designed this wallet to be a simple, expanding wallet that can hold both cards and cash. I have one that is currently holding 11 cards and could probably still fit more (I don't have more cards).