GPU Voltage, help:(

[gorilla show]

I want to push my video card a bit further, but I need to up the voltage to get higher clocks. I cannot use ATI Tool due to it resulting in crashes when playing Call of Duty 2.

I know it is possible on Rivatuner as a power user, but I really don't want to mess with that if possible. Is there another way outside of ATI Tool and Rivatuner?

Or, if someone has a guide to doing so in Rivatuner, then that would be great