Knitting: How do I increase stitches in my last ribbing row?

I'm making a baby hat. I cast on 56 stitches and was supposed to do 8 rows of knit 2 purl 2 ribbing. I did that without any trouble. Now they want me to increase the last row by 8 stitches for a total of 64 stitches. How would you go about doing the increases? (I am using double point needles, but I don't think that matters).