That tool from Tapco SUCKS!
I purchased one and it doesn't work, waste of $8 bucks. The relief hole on the opposite side of the pushing rod is not big enough for the front sight cylinder; so it acts like a clamp. Its made out of such soft steel that I had to bang it on the bench earlier this afternoon to open up the notch for the front site post before I could fit it on to twist the post. The pin that you use to twist the pushing rod keeps falling out.
About the only use I found for the tool, use the main U shaped block as a support for the FSB when you are tapping the cylinder with a dowel/hammer. Or in my case, I was using the back of an empty mag, as I didn't have a hammer with me at the range.
Its an AK, you're not going to hurt by beating it with a hammer/dowel or brass rod.