[Zeke]

OK, use the lacquer thinner and then get some dye of the color you are going back to. You're not going to be able to simply remove the black all the way. But, if you get some of it off, you're on your way to having an easier time of the lighter color covering the darker one. Think of it as removing the surface dye even as the black dye will remain in the pores. And, you won't have a build up of dye that wants to crack.

BTW, you don't mention if you have leather or vinyl. Lacquer thinner is not kind to either, but too much might kill leather.