Ok…start a new ball of yarn…that part is just what it says. This is because you are going to be working on the two shoulders and after you BO you will need two separate balls of yarn.
In the middle of this row you need tobind off center 6 stitches. So for example if you have 18 stitches on that row, you would work 6 sts, BO 6 sts, work 6 sts.
Now you’ll have two sections of knitting that were separated by the BO you just did. Work each section using the correct ball of yarn and BO or K2T or SSK (whatever makes sense) the neck edge ever other row. If you’re looking at the right side of the front, I would work across the left side, SSK the last 2 sts (so you get a left slant on that side of the neck) then K2T on the first 2 sts of right side (right slant) and work across. Work next row even, repeat the decreas row.