In a short row heel, what you are basically doing is knitting across progressively fewer stitches every row. The very first row will have all of the stitches, the second will have one less, and so on until you reach the midpoint of the heel. The midpoint has the fewest stitches (I think you only knit across a quarter of the heel stitches at this point). Once you've completed this row, you then start adding stitches back in, one at a time, until you get back to your original stitch count. Normally you wrap stitches when the time comes to stop using them, because this prevents holes - but holes are part of the effect of these socks, so nothing gets wrapped.
I like Wendy's toe up sock pattern
as a reference for how to do short row toes and heels. There aren't pictures, but it tells you exactly how many stitches you should have at various points during the heel. Just ignore the instructions about wrapping stitches.