You are required to take care of 12 settings for changing Athlon's multiplier. All the 12 slots are using 1000 Ohm SMD-resistors. The first four are R155, R156, R157 and R158 on Athlon's PCB-backside. The following picture should give you a pretty good idea of where they are. Please note that the voltage selection area is right next to it; so don't change the wrong parts!
The next table shows you how to set the SMD-resistors for the clock speed you like.