That looks like the correct place to cut. Just make sure you cut until you see white powdery stuff. That is the glue that holds the lens in place. After that, pry off the black plastic with a slot screwdriver all the way around. The next part is HARD, you need to SLOWLY pry off the lens all the way around. Don't rush it because you can end up with a split lens. Also, make sure the lens isn't cool, or cold. That can cause the lens to snap, also.
Good luck!
