The guy at the store is correct, a fan for socket 7 chip will work with any socket 7 type chip. If memory serves me correctly, I believe you have to take off the cooling coil on the chip, place the metal clip on the two notches on the side, should just lide down, then replace the cooling coil on the chip, and screw the fan on top. The connector should connect to the motherboard that has a small, very small 3 prong plug that reads fan1 or fan.

Not sure if this helps, but hopefully it will.