Help!How to decrease one stitch end of row in 2x1 rib.

Help! Im stuck on sirdar knitting pattern. Pattern says decrease one stitch end of row for 5 rows. How do I do this and stay in 1x2 ribbing?

The pattern won’t stay exactly the same. Work the decrease and then look at the rib pattern on the previous rows. Knit or purl the next stitches so that you maintain that pattern and the columns of knits and purls continue.