Hi,
Assuming you are using IOS, you can power-down a module in a 6500 chassis using the command
"no power enable module " in global config mode where is the slot number of the CSM.
If you are using CatOS then the command would be:
"set module power down "
The CSM should be hot-swappable so you should be able to just pull it out of the chassis, but I think that is a bit vicious if you only want to shut it down.
HTH
Cathy