The first paragraph is the directions to follow next. Start with K18; join 2nd strand of working yarn, bind off the next 36 sts, knit to end.
After completing these instructions you'll have 2 areas of sts on the needle separated by a gap of 36sts for the neck. Purl back across the shoulder, drop the yarn strand, pick up the other yarn strand and purl across that shoulder. Now you're on a knit side again at the armhole edge. Bind off 6sts for the shoulder, work across to the gap, drop the yarn, pick up the other strand and work across to the 2nd armhole edge. At the end of this row, turn and bind off 6sts then work across both shoulders again. Repeat the above.
You'll have 6sts left at each shoulder. Bind off those 6sts, first bind off on a knit row, then bind off on a purl row. That's it!