- With your Device off simultaneously press and hold Volume Up/Home/power buttons until you see Android System Recovery at the top of the screen and a green android laying down with a Red triangle above him in the center of the screen.
- Scroll down using the Volume down button and Highlight "wipe cache partition" and press the power button to select
- When it says Cache wipe complete at the bottom and "reboot system now" is highlight press the power button to reboot
Nope, you won't lose anything or have to set anything back up. The system will rebuild the cache on the next boot. Clearing it will help ensure there's nothing in there that may be causing a problem. I believe that's why it's highly recommended to do it after flashing a ROM. I've read others do it periodically to keep things running as smooth as possible.