Best to use BIOS rather than the windows application since this often sets voltages higher than they need to be (more power, less lifespan). Try
here for a good starting guide.
Most important settings are the core frequency (clock), multiplier and Vcore voltage. For the 2600k which is a very similar chip I started out by just increasing the clock to 45 (i.e. 4.5 with the multiplier left at stock 100x) and increasing the Vcore to 1.39. You can then increase the multiplier if you want and gradually decrease the Vcore until you are unstable.
Make sure you do some stress tests using prime95 or similar and keep an eye on your temperatures using CPUID HWMonitor or the mboard app. Also, note that the voltages specified in BIOS are often lower than appear in windows (e.g. in CPUID CPU-Z) due to vdroop. The value reported in windows is the 'real' one since this is the loaded voltage.