Help with Short Row decreases

I am knitting my first sock… actually a Christmas Stocking, from Annie’s Woolens, and I have started the Short Row heel by increasing using YO for about 18 rows. Now the pattern is beginning to decrease but I am unsure how to start the first row.

Here are the instructions:
First decr. row: (knit side) YO. Knit 9 sts. Slip YO purlwise to right needle; enter slipped YO with left needle tip from front to back in order to reverse the way the stitch is seated, placing it back on theleft needle. K2tog. (this will divide the next YO pair) Turn.

My question is about the part that says Slip YO purlwise to right needle. Does that mean I make a YO and then slip it over to the right needle or does it mean that there will be a YO already on my needle from the increase row previous and I just slip it over to the right needle?

I hope that makes sense. I would appreciate any help at all.

There should be one from the previous row that you will slip to the right needle.

I read it as using the yo from the previous row.

Yeah! Now I can keep going!
Thanks