How do you revive yourself on black ops 2?

If you mean Zombies, it has to be a solo game.

To revive yourself, buy the Quick Revive for $500 (does not need the power to be turned on in solo and is cheaper in solo) and when you go down, you get a Mustang and Sally to kill the zombies, who completelery ignore you. After a while, you will get back up with your weapons. However, you lose all your perks that you buy. You can only get three Quick Revives before the machine disappears. In co-op, Quick Revive costs $1500 and allows you to revive your teammate faster. You lose it like all other perks in co-op when you go down. However, you can avoid this by buying the perk Tombstone Soda. It allows you todie and respawn with your pistol. You can then get all your weapons and perks back by getting the Tombstone power up from where you died.