If your CS9 is like the other Gen3 Smiths I've moved sights on, you're going to be hard pressed to adjust the rear with a punch. Actually, you'll be lucky to get it to move at all. Usually they are so tight they sound like a .22 going off when they break loose. Then again, you might get lucky.
You really need a sight pusher. This is where the shameless plug comes in. Check out this thread:
http://smith-wessonforum.com/accesso...-xd-rated.html
This tool was originally designed to work on Smith Gen3's. I needed to move the sights on a 4006 and was too cheap to buy a sight pusher!