If you have the sts on a stitch holder that looks like a large safety pin, you can hold it in your left hand and knit the sts off it as though it were another needle. If you're using waste yarn as a st holder, you'll have to put the sts on another needle (maybe a dpn if you have a spare one around?) or onto one of your available working needles. Picking up the 9 sts involves creating sts along the edge. There's a video on the Free Videos tab under Tips.
Very cute stockings. Good luck with them.