I'm new, need help on the last step!

Hi everyone - I’m a fairly new knitter and just almost finished my first beanie hat. I have got to last row and can’t figure out what to do. This is what I have: 11 sts on the needle. These are the directions that I don’t understand. [I]Row 22: Purl (which I did and was left w/the 11 sts), put end of yarn in a needle,pull yarn through remaining loops and pull shut to close top. Sew up side seam. Weave in all ends.[/I] I’m confused b/c it seems like I’m not binding off. Do I cut my yarn to do this? Help, I want to finish this hat!

Yes, cut the yarn, leaving about 3 times the length of the seam you need to sew up, plus about 3". Then use a darning or tapestry needle, thread the yarn into it, pull it through the sts on the needle like a drawstring (I usually do this twice), and sew up the seam. You don’t bind off, it’s a very common way to close up the top of a hat, or mittens.