Check out the tutorial and photos here. It looks super easy!
If you decide to try this please post some pictures of your finished project!
I have made bunches of these for my son. He's a bit of a chunker, and we do cloth diapers, so I have a really hard time finding pants that fit him. If you use wool, then you don't even need a diaper cover. I have made these from sweatshirts too and they seem super comfy. With the body of the sweatshirt, I make a sleep sack and just add snaps to the shoulder area. So for like $1 from a thrift store, or free from you're closet, our kiddo can have some pretty hip clothes. Here is the Stinker modeling his latest pair of Wollies. Not too shabby.