How on earth is a cluster stitch done?

I[size=18] cant find any helpful info on this subject online - my sis and i are trying to make our parents a knitted afghan for Christmas, and all was going well until we got the cluster stitch. Its a combination that goes (P3 tog leaving sts on lefthand needle, YO, P all 3 sts tog) I’ve tried following the instructions exactly, all to no avail. The result is always an unfortunate tangle. I taught myself to crochet and so far all the knitting sts I have learned - I don’t know why this is so difficult, but if anyone could explain the proscess of this stitch in more detail, I would be so grateful and might not even hate knitting anymore.
Thank you in advance for any assitance anyone can offer.[/size]

IHK do you have the rest of the pattern?