Those are the directions for the back armholes but you only need to work the bind off of 3sts at the beginning of the row (as given in the directions) and then, on the next RS row, a bind off of 2 sts at the beginning of the row.
When you get near the end of this bind off row, start doing the neck decreases. Work to the last 5 sts, SSK, p1, k2. From now on you’ll be working the dec at the armhole edge (beginning of RS row) as given for the back and the dec at the neck edge (end of RS row) at the same time.
Under Shape Armhole and Neck it tells you how to work the neck dec, (work to the last 5 sts, SSK, p1, k2).
Work even means to continue without inc or dec.
A 0 for your size means skip that direction. Go to the next step.
Thanks for all the information incuding the pattern link!