Okay, you'll be working on only the 24 stitches for the heel flap. The instructions you listed appear to be for the heel turn which comes after the flap. The heel flaps I've done were like this -
Row 1. slip 1, k1 across (the 24 stitches) turn and work on back of flap now -
Row 2. slip 1, purl across
Repeat rows 1 and 2 till it's as long as you want.
Look in your book for the heel flap instructions and see if that is what they want you to do. It's pretty generic so it may be in a general area rather than with each pattern. Here's the tutorial I learned from. It's on DPN, but if you're using circs it'll still work. The center number, the blue one, is done on 48 stitches as well so it would be the one to use for example.