simple newb guide to extruder fan installation

inb4 look at the sticky - the sticky has a preerequisite for a panelonu installation. I could really do with a simple step by step help as to how to install a extruder cooling fan on the original solidoodle 2 with the original motherboard NOT the ramps board

Im hoping to get a job in 3d printing and i need to flesh out my portfolio so having the fan to get the quality up is pretty critical for me at present.

Everlasting thanks in advance :-)