The handbrake is meant to be self adjusting and usually works well. Sometimes people don't back off the handbrake before doing their rear pads and then it's all out of adjustment

handbrake adjustment.JPG
If it's just handbrake cable adjustment you're after then that's pretty easy. Remove the plastic guard at the rear of the centre tunnel and the adjustment nut is there.

About 3 clicks on the handbrake is good. Make sure your car rolls easily with the handbrake off once you've adjusted it:)