PLEASE HELP! need to unroot!

view story

http://androidforums.com – i need to unroot my htc evo 4g and have no idea what to do. i know it was rooted with unrevoked by a friend. the only info i think is useful would be supersonic evt2-3 ship s-on hboot-2.10.0001 microp-041f touch panel-atmelc03_16ac radio- oct 15 2010, 12:07:00 (General)