How to get the discoloration and hard lumpiness from butt injection under control if you can't remove it?

In areas where the material can not be removed, injection of local acting steroid (kenalog) might prove helpful to limit  and control the inflammatory process.

If buttock injections you had are silicone or hydrogel. Now developing granulomas and chronic inflamation. At least part of the injected material and the lumps can be removed.  This will cause irregularities of the buttocks that can be improved later with buttock fat graft or buttock implant. By removing most of the material injected, will decrease the inflammatory response and the pigmentation.