PP KKKKK K3Tog YO K YO PP YO K YO SSSK KKKKK PP
I cound that you should have 24 stitches when this is done.
When you do a yo before a knit, bring the yarn to the front, knit the next stitch. That will create the first YO before the K.
To YO before the purls, you need to bring the yarn forward as if to purl, but bring the yarn back up over the needle and to the front again to create that yo. Maybe that's where you went wrong?