I think in the account setting there is an option to close the account. but if you don't want to struggle then just click on your ads for several times and your total account will be banned!!! easiest way dude
Yes click own ads is easiest way, but what if that crazy man wants Adsense account again then he will not be able to get it again.
You might want to check out on Google directly : www.google.com/support/accounts/bin/answer.py?answer=32046
Why u want to desabled ur account? or u want desable ur freind ac or any other publisher account? BullShit