8.75 diff - metal in oil (pictures). Is it ruined?

Take the 4 cap bolts out, and spill the case out onto the bench, ring-gear end closest to the table. See those small headed bolts sticking up? Take every second bolt out. Then back the rest of them out three turns each and move to the next one. They are under pressure from the springs inside. When they get close to coming out, put one hand on the case and press down to keep the upper half parallel to the lower half so you don't mess up the threads. If you see two cross pins, indicating a TracLoc, I suppose you could stamp the case-halves to make reassembly easy. But the cone type is obvious which way to align it on reassembly.
Once the hat is off just spill the guts on the table. On the 4spider type, I keep each spider on its pin to ensure long life at reassembly time, unless the pins are puked, then it don't matter.