Welcome to KH and to knitting!
Although it looks like your stitches won't all fit, they indeed will. A P2tog uses two stitches to make 1 stitch, and yo's or (also called in this pattern "yrn/yo")
do not use a stitch to make a stitch. So you will be wrapping the yarn around the needle twice. Also note: Since these yo's come before a purl stitch, you'll need to wrap the yarn in the same way that you wrap it to make a purl stitch.
Take a look at this video if you need a refresher re: yos:
http://www.knittinghelp.com/video/pl...er-continental