I'm not sure if there's a video for that exactly. Here's what you will do.
Knit the stitch as you normally would, but DON'T slide the original stitch off the left needle yet. Bring your working yarn to the front of the work and purl the SAME stitch. Still do not slip the original stitch off the left needle. Again bring your working yarn to the back and knit that same stitch one last time. NOW you will slide the original stitch off the left needle. So now you have three stitches where there was originally only one stitch.
You should end up with the same # of stitches to start the next row. P3tog is a double decrease, but K1P1K1 into the same stitch is a double increase so you will be left with the same number at the start of the next row.