I can't say it often enough, BE CAREFUL! Start this procedure only if you have experience with SMD-soldering! You require a professional heat-adjustable soldering iron with a very fine tip. Use a very fine tool to keep the SMD-resistor in place, don't overheat the PCB, don't scratch around on it, don't rip off a half-soldered SMD-resistor, because it kills the PCB, and be careful that your SMD-part doesn't stick to the tip of your soldering iron!
Don't do it if you feel insecure in any way! Don't do it altogether as long as you haven't got a damn good reason to increase the performance of your Athlon. In most cases Athlon performs better than anything else anyway. Don't do it just for fun and don't think that it increases your pecker-size in any way. Even the crazy die-hard overclockers should have learned that by now. You ARE risking the life of your CPU! Don't ever forget that!
You might have found out already, I mistakenly used the picture of an Athlon 600 backside and an Athlon 650 front side. Don't look at the settings, those pictures are only used as a map to make finding the selection areas easier. The tables show the correct settings.