I couldn't get my computer to show me the whole pattern, but this is what I'm picturing, but I could be all wet.
Make a crochet chain about 110 chains long with waste yarn. With your hat yarn pick up 99 bumps on the back of the chain (leave about 5 chains on each end and where you ended the chain tie a loose knot to mark the end of the chain to unravel when the time comes.). Join to work in the round. Knit 6 rounds. Take the provisional cast on out and put a smaller circular needle into the live stitches produced. Fold the piece up so that the two needles are next to each and parallel to each other and the rev St st side of the folded piece facing out, with the needle you knit the 6 rows with, knit the first st on each needle together as one, repeat around, chuck the empty skinny needle and keep working with the needle you knit the 6 rnds with.