Permitting a Bedroom, without a General Contractor?

[Thomas Corey]

One of the bedrooms in my rental is not permitted and I have some questions about rectifying that. Do you have to have a General Contractor to do this? And if not, how does one go about doing so? And, does anyone know someone who can help with getting this permitted in my area?

Thanks,
Tom

(Los Angeles-Long Beach, CA)