No problem.. If you go to the bios download page for your motherboard, which, I think is this but do make sure:
ASRock > Products > N68-S
Click onto this bios section and you'll see this page:
Link Removed
Click where I've arrowed and you'll then see this appear:
Link Removed
Read the instructions carefully until your sure of the procedure. It might help to write them down? Anyway just go slowly, follow the instructions and you'll do fine.