Cast on 90 stitches (which you have done)
ROW 1: This row is going to have: a)19 stitches in 2x2 ribbing, b) one repeat of the cable pattern in chart A, c) 18 stitches in 2x2 cable, d) a second repeat of the cable pattern, e) 19 stitches in 2x2 ribbing. Place markers between these section
ROW 1: a) k1, p2, k2, p2, k2, p2, k2, p2, k2, p2 [place marker] b) 17 stitches from chart A [place marker] c) p2, k2, p2. k2, p2, k2, p2, k2, p2 [place marker] d) 17 stitches from chart A [place marker] e) p2, k2, p2, k2, p2, k2, p2, k2, p2, k1
On wrong side rows, work the stitches as they appear with the wrong side facing you.
Sections a), c), and e) remain the same until 11.25"; b) and d) follow the chart, repeating the 16 rows (only right side rows are shown). Then you change to reverse stocking stitch and make decreases in the first right side row.
I think you'll be fine once you get the first row settled. Check your knitting carefully for the first few rows to make sure that you are reading your knitting correctly on the wrong side rows.
Post again if any problem
Salt Spring Island