Always unplug your air conditioner before cleaning.
The air filter behind the inlet grille should be checked and cleaned at once every 2 weeks (or as necessary) to maintain optimal performance of the air conditioner.
How to remove the air filter
1.The grille may be opened from the top for easy maintenance after instal
2.Open the inlet grille by pulling off the exposed door on the top of unit(based on the installation).
3.Pull the tab slightly to release the filter. Pull the filter in the same d as the opening.
4.Clean the filter with warm, soapy water. The water should be below 40oC(104oF).
5.Rinse off and gently shake off excess water from the filter. Let it dry replacing it.
DO NOT use your air conditioner without the air filter in place.
To clean the front panels or the cabinet DO NOT use harsh chemicals, abrasives, ammonia, chlorine, bleach, concentrated detergents, solvents or metal scouring pads. 
Always use a soft cloth dampened with water or mild soap and water solution to wipe the front if the cabinet.