Removing alloy paint?

Previous owner looks to have sprayed the sport alloys black. They're now getting chipped and paint is flaking off in parts. I can see the standard Silver colour underneath and was wondering if there's any products ect that could just remove the black to leave them silver? Thanks
 
If you take them to a decent refurb place they will acid dip them which takes them down to the bare metal
 
Don't know of any way to get them back a single layer of paint really, were they just sprayed with a can?

Sounds like you'll need them completely stripping as Ben says.
 
Would that bit remove all the lacquer and protection though? It looks like he's just attacked them with a rattle can! Lovely and shiny underneath to what I can see. Just wanted the top layer of black off really. Cheers