A whole lot depends on the mindset/attitude of the person in charge of vehicle things at the tax assesor's office you go into. The forums have had some Texas guys who could convert their HDT from commercial to private, like a big pick up pretty easily. For me, at my local tax assessor's (El Paso) it was impossible. To be able to drive it around while the T2000 was getting worked on I resorted to a Montana LLC which did the job but sort of puts you on borrowed time; I was able to get that to work out quite nicely but it sure took some hoop jumping. My conversion was to an RV-garage and when I got the rig to that point, even with pictures etc. I still couldn't get my local assessor to work with me. So I got my pictures and papers all in order, went to a different tax assessor who turned out to be a fairy godmother, and i got Motor Home registration with car plates. Details, details, details, and I think it would have been harder if my conversion was just to a to a toter with minimal RV appliances on the truck itself.
Some raw guidelines:
1. From the start avoid commercial registration, unless you're OK with that for other reasons. They tried to send me to the TX DOT here but that would have hooked me into commercial and that get harder to get out of.
2. Visit your local tax assessor's office (might as well be convenient at this point), find the responsible person, tell them what you would like to do and ask them how to do it. Let them tell you, don't try to put words in their mouth. A picture of a rig like you might start with would help get them oriented; many can't hardly imagine what would be going on. Try to make a friend here, or if you can't try somewhere else.
The devil was sure in the details for me. PM me and I can go into that, unless more on this forum want to see all that, then I could go into that here.