So im not completely sure if this still works but i did it once but it also resets your level to 1 of that prestige.
You need

atchBlocker, lvl. 50 in combat training, a friend.
1. You delete all patches for black ops.
2. Start the patch blocker and go to multiplayer.
3.Friend needs to start patch Blocker also.
4.Have a friend invite you too a lobby.
5.Open playercard and go to where you edit your emblem.
6.Have your friend switch it to combat training.
7. Hit Cancel and go down to prestige.
8.Hover over prestige and have your friend switch it back to player match.
9. Prestige and it should reset.
I did it once with my friend while he was 2nd prestige and it did exactly what i said. Just not sure because your at the final prestige.