Selling Colorado bike in California

I have a 2003 CR250 that I purchased in 2009 in Colorado. No title/MSO just bill of sale.

They do not title offroad bikes in Colorado. Have never bought or sold one with a title in 25 years.

I purchased OHV passes for this bike for 3 seasons.

Now in California and would like to sell. Hearing this is a big deal for people out here.

Any idea on how to get some kind of paperwork for this thing?

I have done a lot of reading but haven't found a straight answer..