Safety notice!
Ensure the load frame is powered down and disconnected from the mains supply before beginning.
Remove the screws holding the back panel to the load frame. (See picture right).
Identify the fan on the back panel. Indicated by the red box in the picture on the right.
Remove the fan as indicated.
Fitting the new fan is the reversal of the process used to remove the old one. As is fitting the back panel to the load frame.