Whitening yellowed plastic?

Hey guys,
Sorry if this is in the wrong part of the forum and feel free to move it. I have been trying to find out if there is a way to whiten slightly yellowed plastic. I have seen some techniques on how to do it online but they all require that I submerge the plastic in some chemical bath type deal for lengths of time. The figure I want to whiten (All white aerialbot limb from Combiner Wars) has stickers and other paint applications so I was hoping to do spot whitening as it only has parts that have yellowed (I kept it in a bad place apparently...) I'd prefer not to sand it as that would likely lose the glossy finish. I'd prefer not to have to buy a new one too...
Sorry if this is in the wrong part of the forum and feel free to move it. I have been trying to find out if there is a way to whiten slightly yellowed plastic. I have seen some techniques on how to do it online but they all require that I submerge the plastic in some chemical bath type deal for lengths of time. The figure I want to whiten (All white aerialbot limb from Combiner Wars) has stickers and other paint applications so I was hoping to do spot whitening as it only has parts that have yellowed (I kept it in a bad place apparently...) I'd prefer not to sand it as that would likely lose the glossy finish. I'd prefer not to have to buy a new one too...