Bought car from a scammy dealer and now they’re out of commission

Hello,

I bought a used car a couple of months ago and I’m trying to renew my registration. I am already late to it and when I try to renew it online, it is registered to the old address. I can’t contact the dealer as they went out of business and o don’t know what to do. I can’t change the address online. What do I need in order to change the address at the DMV and to pay the late registration?