Your best bet is to have a zygomatic osteotomy. The fracture lines are re-broken and the bone is put back into the correct position and held there with plates & screws whilst it heals. Your eye socket may need some work done to it as well, as the movement of the zygoma could create a floor defect. Your cheek fat may also need to be resuspended. There will need to be several access incisions (eyelids and mouth), and depending on how bad the fracture is, you may need a larger incision in front of your ear and up into your hairline.
This is best done in a specialised craniofacial unit (or by a Board Certified Plastic Suregon whom has done a fellowship in Craniofacial Surgery) rather than by your local Plastic Surgeon.
There are other methods of camouflaging the problem, but without solid foundations (bones), the house (cheek/face) will always look odd.
Hope this helps
Dr Gavin Sandercoe