I think if you just do exactly what they say, it'll work out. Knit into the fourth stitch, then knit the first stitch and purl the next two, sliding the fourth stitch off when you finish the second purl. Does that make sense?
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog