Step 5: Ribbing
This step is optional, and depends on if you want the brim of the hat to be ribbed or rolled.
For ribbing, work the hat in a Knit 2, Purl 2 for about an inch. I like to use a stitch marker to indicate where I started ribbing so I can stop at the same point, but it's really not necessary.
For the brim to roll up on itself, just start in continuous knitting.