download msi afterburner
dont touch voltages
increase core speed by maybe 50 to start, then stress test (furmark or unigine valley for 20 minutes) and if it passes without any type of fail or crash, then up it by another 10 and repeat the process until it does crash. when this happens, dial clock speeds back by 20 from where they failed, and save the overclock profile, thenrestart computer
once you have done this do the same for the memory clock
when all is said and done, you will have your overclock.
if you feel like you need more, and temps are still really good (under 80) then you may adjust the voltages slightly, but you won't get much more out of it than that