Turn off the power supply leading to your mini-split unit.
Find the intake grill and lift it up from the bottom.
Remove the plasma filter and soak it in water and detergent. Choose a detergent with low alkaline. Don't scrub the filter; swish it around or let it soak in a bucket to clean it. Rinse thoroughly and allow it to dry overnight before returning it to the mini split.
Vacuum the mini split using the hose attachment on your vacuum.
Wipe down the mini split with a damp cloth and dry thoroughly.
Remove any debris that has collected around the exterior unit of your mini split. Sweep the unit down with a broom to remove any dirt.