Modify sock pattern for magic loop

I’m using this: http://www.wiseneedle.com/patternpage.asp?pattern=knitpatksox sock pattern, and I’m making my first pair of magic loop socks. My question is regarding the cast on.
I’m supposed to do a figure 8 cast on with two needles (no problems there). But as the directions are for 4 dpns, it then says “Take a third dpn and knit across the top needle. Take the fourth dpn and knit across the bottom needle.” How can I modify that for magic loop knitting?

Just use the needle end that you would normally use to knit one side of the sock on magic loop (the one opposite the stitches you want to knit), then switch. Really, you’re just using the same method you’ll use to knit the entire sock.