I can never remember my password to the Lionbrand site, but the directions sound like almost every other sweater.
What you're going to do is make the front of the neck lower than in the back. In order to do that, you knit across to the center 8 stitches. Then, using a second ball of yarn, bind off the center 8 and finish the row.
Now you'll have two strands attached to work each side of the neck. You work one, drop that strand and work the other, both on the same needles and at the same time so you know that they'll be the exact same length.