When I read it, I see it as, a K1 edge stitch, p2k2, then p4k2 across, ending with a k1 edge stitch at the end.
The right side looks like you'll k4, p2 all the way across. With an edge stitch at each end. That can keep you at 80 stitches.
If after that you k the knits and purl the purls as they face you, then you're getting a k4 p2 rib all the way up. Is that what the pattern looks like? Or is it a staggered rib? In that case you'd keep the p2, k2 beginning and end of the ws rows.
You'd still keep the k1 edge stitch on both edges, though.
It's hard to say without the pattern or a picture.
Maybe if you type out those first few directions exactly as they appear, it might offer some insight.