There's a couple of ways to work these decreases. You're doing the right thing by eliminating the YON and going to the K1. That'll decrease one stitch for the next rows which probably have some decreases in pattern. The easiest way to figure out where to start the pattern is to look at the previous rows, read your knitting and see how to continue the eyelets so that the pattern doesn't break. Sometimes it helps the count across the row backwards to figure out where to start.
Another way to do it is to eliminate one repeat of the pattern at the edge and work that area in purl sts just as the pattern row originally began with the P5. Then you continue with a full pattern repeat at the next column of eyelets.
It's much too pretty a sweater to sit in a closet.