Go to the Free Videos tab at the top of the page and click on Increases. There you'll find the video for kfb.
Every st has 2 legs, one over the front of the needle that we normally knit into, and one over the back. So knit into the st as usual, leave it on the needle and also knit into the back leg. There's 2 new sts on the R needle and you drop the original st off the L needle like you usually do.