absolutely no way. the print dyes the white base it is no longer white.
Not worth the time or labor to do that, dyesub metal is cheap.Probably hard but on cases the ink really is only penetrating the sprayed on coating on top of the plastic. it maybe possible to remove the coating with for example toluene and then re-coat.
Forget it. Dye sub creates a molecular bond (dye and substrate are sharing electrons together) the only way to remove is to destroy the surface.I have printing QC fail phone cases. Want to remove the sublimation printing. Is there any chemical to remove the print?