I just got property taxes reduced for 4 similar properties to yours in the area by doing this! You will need to submit some comps, so feel free to contact me direct, and I would be happy to provide you with the information you need.
Keller Williams Realty
Visit the Los Angeles County Office of the Assessor and you will find a form for Decline In Value Request (form RP87). Please send me your contact information or email and I can prepare a full market analysis for your property.