Just follow the HS instructions backwards..
AMD 64 HS Install' ">http://www.geocities.com/ewilk99/index.html or see Chapter 4 in
AMD's Opteron Builders guide' ">http://www.amd.com/us-en/asset...nd_tech_docs/30925.pdf
So unlock the clip, turn the lever, unclip the HS from board and pull heatsink straight up and evenly.