You can't. Overdrive is an option that is built into Catalyst Control Center, and therefor, you can't get it separate. I would suggest the OP reinstall the drivers using the default settings. Then start CCC, click on the lockpad and OC to your hearts content.
Edit: I think the OP is talking about AMD Overdrive, which is the software for AMD CPUs and Motherboards. You cannot overclock a graphics card from it.