I can't tell you how to overclock RAM, but for a CPU...
1. Keep pushing the multi up until it doesn't boot on stock voltage
2. Bump the voltage a bit
4. Once you've got it as high as you can go, stress test it.
5. (Optional) Push the BCLK up a bit
If it fails the stress test and crashes, lower the multi/BCLK a bit. If it still crashes, lower the voltage.