Turn off the light and fan in your stove's hood before cleaning. You can also turn off the electricity to your stove at the breaker box.
Spray a degreasing cleanser onto the outside of the stove's hood and wipe it clean with a soft cloth.
Remove the filter from your stove's hood. Usually the filter simply clips into place with a small latch. If your filter is metal, you can clean it yourself. If the filter is made from activated charcoal, you will need to replace it with a new filter. Check your stove's manual if you are not sure which type of filter you have.
Pour enough degreasing cleanser into a bowl to cover the metal filter. Soak the filter for at least 30 minutes to allow the cleanser to dissolve as much grease as possible.
Wash the metal filter in hot, soapy water. Use a liquid dish soap that cuts through grease and oil.
Allow the filter to dry on a towel before replacing it. Once it is dry, put it back into the stove's hood.