Help! How to knit a flat disc from outside edge to center?

[MsB]

OK I am officially annoyed with this hat . It is driving me batty!

I have seamed an approx. 4" wide rectangular band and picked up 74 stitches around the top edge of the band. How can I now make a flat disc for the top of the hat with those picked up stitches?

All the instructions I have been able to find are for more stitches. :::sigh:::