Beginner--how do i decrease in lace rib?


I’m a beginning knitter who’s worked through a few basic scarves and hats, and learned how knit, purl, do some lacing, normal ribbing, etc. Right now, I’m making a hat and using a lace rib pattern that repeats in sets of 6 stitches and 4 rows, as follows:

Rnd 1: *P1, K2; rep from * to end of rnd
Rnd 2: *P1, YO, SSK, P1, K2; rep from * to end of rnd.
Rnd 3: As Rnd 1
Rnd 4: *P1, K2tog, YO, P1, K2; rep from * to end of rnd

the pdf for the pattern can be found here:

:knitting: I’m making the hat out of a wool-acrylic blend worsted weight yarn on 4 double pointed size 8 needles, with a gauge for a 4x4 inch square of 18 st X 24 rows. I have 84 stitches total, with 21 on each needle. Since the pattern I’m using for the lace ribbing is just something I found, I have no instructions for how to decrease and I can’t figure out how to do it. Any advice?

I think this Fusilli Beanie is the same pattern or very similar. You can see how she decreased and maybe it’ll work for your hat.