This video knitting tutorial will help you learn how to knit the purl two together decrease (p2tog). This method of shaping your work by removing stitches is used on the purl side of your fabric, usually the wrong side. It creates a left leaning slant on the purl side and a right leaning slant on the knit side when doing stockinette. It mirrors the slip slip purl (ssp) and looks the same as the knit two together (k2tog)
Step 1: Insert your working needle into the first two stitches on your main needle, purlwise.
Step 2: Wrap the working yarn over the working needle, going over the top and around the bottom.
Step 3: Push the working yarn through both stitches on the main needle.
Step 4: Pull both stitches off the main needle.
Example of the Purl Two Together Decrease right side close up (click for larger)