Might be wrong but pretty sure you will have to have the vin or lack of verified... either by law enforcement, DMV or I think there might be some private "for pay" certifications. (Call your local CHP office & ask)
You will also have to have it weighed at a certified scale & bring that to the DMV, (but if your going to move it over the roadway... be sure to get your temp permit first. )
(Actually... they might have done away with the weight fees for trailers, so ask first!)
Did it a few years ago & it wasn't too bad... of course sometimes it all depends on which DMV employee you get!
Good luck, DanDee