Originally Posted by HeLeX63
Personally I prefer EVGA Precision, but MSI Afterburner is fine. You download the software and install it.
Open up either one you have decided to download. You should have a few available sliders you can adjust. The Core Clock and Memory Clock.
Start with the core clock first, increase it initially by about 50-75MHz, then play a game for a bit. If it runs and doesn't crash, increase it further until you notice instability or crashing.
Do the same after you have found a stable Core Clock frequency, and repeat for the memory as well. Don't forget to press APPLY for the new speeds to take effect.
Do not worry about crashing, it will not damage your card in anyway, unless you somehow fiddle with a voltage tweak (advanced users) and accidentally pressed apply to a voltage of 1.400 for example, which will pretty much blow your card, physically.
Good luck with your overclock