decrease and keeping pattern correct in k1below p1 ribbing

Hi, I am a novice knitter and am knitting a sweater “rib panel sweater in freedom spirit wool”. Pattern says keeping patt correct, dec 1 st each end of next and every following 6 row until 117 sts rem.
patt is: row 1row sl 1, k to end; row 2 sl1 k1 below , p 1 rep from * to * to last 2 st k 1 below k1, How to I keep my ribbing aligned while reducing and have a nice straight rib

Welcome to KH!
You’ll have to give up the rib pattern for the first and last couple of sts in the row in order to maintain the rib pattern that you’ve established on the previous rows. Once you’ve made the decrease, look at the previous rows to see where you are in the rib pattern, and follow that pattern.

thank you so much , makes sense , I will do this