How do I fix raised wall patch job?
Sand them flat (or even slightly dished). Apply joint tape to any cracks (my personal preference is mesh, though you'll find lots of opinions). Apply all purpose joint compound in numerous thin coats. (Purists would have you do the mesh tape coat with a setting compound. Opinions vary, but setting+mesh is technically better.) Let dry completely between coats. Sand off high spots between coats. Eventually get to the point where you're feathering out the patch with a 12" knife. Do a final sand. 

If you can handle the truth, shine a bright light sideways along the patch. That will show defects.

If you've passed the light test, prime and paint. Congratulate yourself for a job well done.