5. Then remove the screws around the bottom perimeter of the unit and remove the vented side walls. Be careful not to damage/bend the fins of the heat exchanger while removing the side walls.
This is what my Unit looked like disassembled.
Very dirty as you can see, a combination of dog hair, vegetation debris, and dirt.
6. vacuum up the large debris inside and out, move the vacuum hose up and down on the heat exchanger so you don't bend the fins. Also be careful not to cut yourself on the sharp fins.