It is not advisable to OC on the stock HSF supplied by Intel. They are not that great for removing heat.
But if you really want to do it still, you are more than welcome to try.
Here is a small chart that should get you started.
Please monitor stability and temperatures carefully. This needs high vigilance, else you burn your system, or render it useless.
Download the following:
1. CPU-Z (to see successful OC once you reach the desktop)
2. RealTEMP (to see the temperature gradients as incremental load is applied)
3. Prime95 (used with RealTEMP as the CPU load application).
4. OCCT (used to overall stress the system, and check your PSU stability)
5. Lavalys Everest (to have constant monitoring of system specs)
Be prepared for a lot of restarts/system crashed/BSODs. Do the increments so the change is not to drastic.
Last but not the least: Be careful, and do not hold the forum responsible for any system failure. Best of luck.