1st dec row - k2, p2tog, k2, p2 - repeat
2nd dec row - k2, p1, k2, p2tog - repeat
3rd dec row - k2 tog, p1, k2, p1 - repeat
4th dec row - k1, p1, k2tog, p1 - repeat
in between each dec row, work the new ribbing pattern you've made
If you need to dec more sts, do a row k1, k2tog, p1, k2tog, etc - then k2 tog all the way around.