Disconnect all audio cables from the back of the mixer. Unplug the mixer's power cable from the nearest electrical outlet or surge protector strip. Relocate the mixer to a sturdy work surface.
Use your fingers to remove each knob from the surface of the mixer. There are a total of 62 knobs to be removed.
Remove the 24 Phillips-head screws from the mixer's top cover. Unscrew the remaining Phillips screws from the mixer's back, front and side panels.
Grasp each side of the mixer's top cover, and lift the cover off of the console's bas but do not remove the top cover completely. Lift up only slightly to access the inside of the mixer's housing.
Locate the cooling fan assembly inside the mixer, and disconnect the DC power cables from the main internal circuit board. Remove the Phillips-head screws fastening the fan assembly to the base of the mixing console's casing. Lift the entire fan out of the mixer.
Use a can of compressed air to blow out all dust and debris from inside the mixer where the fan mounts to the casing. Place the new fan inside the mixer, and align the screw holes on the fan with the screw holes on the base of the mixer. Fasten the new fan to the mixer with the screws included with the fan's replacement kit. Connect the fan's DC cables to the appropriate connectors on the main circuit board.
Place the mixer's top cover back on to the console. Re-attach the top cover's retaining, Phillips-head screws. Replace the 56 knobs on the mixer's surface. Plug in the mixer, and power it on to test the new fan.