It was very easy to follow, much better than any written directions I could do for something like this. I had some old Gerber sleepers that I will not be re-using for a future child (not a good fit). I held on to them for the fabric because they were pretty colors and very soft.
I took out the zippers and saved them for later use. Then I cut two fat strips from the shoulder to the heel. The Pin shows you using a loop of a t-shirt, so, not being sure if that was necessary I cut a slit down the middle of each strip. It did make the process a little easier, but your pieces do not have to be attached for this to work right. You don't even need 4 strips. Any even number could work. Being perfectly neat is also not necessary because of what you will be doing next.