Need help with pattern

I'm making a simple bottle cozy ( and I'm stuck on the pattern. I have made the front and back with the v-neck bottle opening and I'm trying to figure out how to do the sleeves. The part that I'm having a problem with reads: "With right side facing, attach yarn at side in the first row end of the neck division; ch 1, work 12 sc evenly across the same row end and the next 15 rows; turn - 12 sc."

I think the neck division is the row that divides the front from the back, but I'm not really sure where to go from here. Any ideas? TIA!