Ok, here are the step by step instructions:
First I put the ribbon through the center. Used a lighter on the edges to seal them.
Next, my husband cut board for me for the seats (to fit inside the open end), since I want to use them for storage. The cut has to be pretty exact to fit on the lip inside of the crate. I did check with my local hardware store, and they said they would cut it for me. (Back up, just in case dh couldn't do it!)
Then I traced the boards that he cut onto the back side of the bath mats. When I cut them, quite a bit of the carpet pieces fell out. I pulled all of the loose ones off of the pieces I was using. I was a little concerned that more would fall out, but the rest of them seem to be in there very tightly, so fingers crossed on that one.
Then I hot glued the rug pieces onto the boards. I started with the center, and then went around and did all of the edges.
Lastly, I glued a piece of ribbon across the top, to use as a "handle" to get the lids on and off.
Hope that's helpful!