OK; I'm having difficulty accessing the LA County Assessor's office; Orange County's is much simpler.
However, by looking through the various web sites, I see your AIN (Assessor's ID number) is 5684-018-021. (The website where I found that is at http://maps.assessor.lacounty.gov/GVH_2_2/Index.html?configBase=http://maps.assessor.lacounty.gov/Geocortex/Essentials/REST/sites/PAIS/viewers/PAIS_hv/virtualdirectory/Resources/Config/Default
It shows as defaulted in 2015 (it appears you missed the April 2015 payment), with the redemption amount as $517.95. The amounts due on December 10, 2015 and April 11, 2016, are both $414.04. Elsewhere on the website it states that you need a PIN to make payments; that PIN being found on the tax bill.
The change of address you file with the Assessor's office can be obtained at http://ezforms.assessor.lacounty.gov/Form/Fill/10 (you fill it out online, print, sign, and mail): and is mailed to
Office of the Assessor
500 W. Temple St., Dept. M/A
Los Angeles, CA 90012
You may also need to let them know separately that you don't live in the property, to revoke the homeowner's exemption for future years. IF you lived in the property on January 1, 2015, it's OK for this year.
Alternatively, you can handle the change of address at an assessor's office.
The website where you can make determine the amount of payments, or make payments if you have a checking account or credit card, is http://ttc.lacounty.gov/
I hope I've answered your question completely. If you need more help, please don't hesitate to ask, but I'm going to be out for the next couple hours, and then out from tonight through Friday morning.