These are easy to open and properly clean.

There are about 9-10 screws that can be accessed with a regualr phillips screw driver on the back of the unit. Some of the screws are deep in the recessed plastic and you will need a longer screwdriver. once all of them are out the rear plastic cover slides off straight back. Make sure the power is unplugged.

Once the rear cover is off there are 3 or 4 screws on a top insert that will need to be removed to take the front off. It is clipped in on the sides and there will be a ribbon cable to the top control panel. Be careful not to rip it apart- and disconnect the control interface. I did not take pictures for this step-sorry.

Now that both of the plastic covers are off you can see just how much accumulated dust this thing has sucked in unfiltered. *once again make sure this is unplugged!*

The lower cooling system is going to be packed with stuff drawn into the cooling fins. Carefully wipe downwards with a wire brush- the fins are very fragile and any sideways movement could damage the fins. The fins are difficult to access around the condenser pump and hoses.

Be careful not to damage anything. A wooden bamboo stick is helpful to get the bits the brush cannot reach. A vaccum HEPA is also really helpful to suck this gunk up. Be sure to clean any gunk up around the entire unit and use the wire brush on the top fins as well.

once the unit is reasonably cleaned up you can carefully replace the front- attach the control wire. Reclip the front and then maneuver the rear cover into place- it should align right up but you may need to nudge it a bit to get it right. put the screws back in and give it a try. Provided you did everything correctly it should power on.