I know it's been awhile since you posted this, but I thought I would post to help someone in the future (I had to tear it out a few times before I FINALLY figured it out).
my pattern was a bit different (skip 2 sts and knit 3rd st on LH needle, k first st, k second st, slip these off... in other words no P1 first -in other words, no P1 first)
Here's how i did it.
Slip the first 2 stitches onto another similar sized knitting needle. Pull that needle to the front to get it out of the way. Knit the 3rd stitch. Slide the 2 stitches from the 3rd needle back onto the left needle. Then knit those 2 stitches. (then P1 or do whatever the rest of your row requires.)
**Note... when you slide the 2 stitches back onto the left needle, do it just as you took them off. Don't try to knit off the 3rd needle.
Hope this helps!