Just start by bumping up the blck 1 or 2 at a time. Bump it up and then run OCCT for about 10 min and make sure it's stable. Don't worry about blue screens - they're a part of overclocking. If you bump it up 2, say, from 133 to 135 and it runs stable you're good. Try it up a couple more. when it becomes unstable you will probably need to start bumping up the vcore (cpu voltage) up 1 or 2 +'s. One thing you will REALLY REALLY need to keep an eye on is the temps. Your chip is designed to run at 72.7*C
. You can run them hotter than that but it decreases the life expectancy the hotter and longer you run them.