Call of Duty: Black Ops II

This is probably the easiest achievement, and it can be done on any difficulty.
This achievement is done by opening a door while in the Afterlife state. I should point out that playing in the Solo Play game list entitles you with up to 3 uses of Afterlife, rather than 1. Play in Solo Play to get more chances if you run out of time in Afterlife.

As soon as you start the game, revive yourself from afterlife mode then kill some zombies to get 1000 points. Proceed by opening the spawn door by the M14, up the stairs then hop off the catwalk to the ground floor. You should see an MP5 on the wall, as well as a grey door with the Afterlife symbol on it. Proceed around the corner and to the red electric shock box. Use it and you'll enter Afterlife. When you are in Afterlife, you should see a 'portal' in the wall beside the MP5 (this was where the grey Afterlife door was). Proceed through the portal and jump over the obstacle. Once at the end jump on the pipes, and jump again to the platform above you. Continue along the platform and you should see a blue shock box. Shock it* (press RT) and the achievement will unlock.

*This unlocked the gate entrance leading to the Shower room nearby.

Another spot you can do this (if you don't do the Shower room) is the Warden's Office. You must have 2000 points total to get to the area by the Warden's Office. From the spawn, buy the M14 door, continue along the catwalk and around the corner to a gate that cost 1000 (it's by the red shock box from the previous method). Buy the door and head to the lower floor. Up ahead is the Warden's Office. Use the red shock box on the wall by the Fan Trap in front of the Office and you should see a portal above the door to the Office. Jump in the portal, go right and continue through the second portal to another blue shock box. Shock it* and the achievement will unlock.

*This unlocked the Warden's Office.

Here is my guide from my channel, Toslow Gaming. In the beginning, you need to make at least 1000 points (use the 2x multiplier). Then, make your way to the Cafeteria. Past the cells is a power box to make you go into Afterlife mode. You can kill yourself as well. When you spawn as a poltergeist, to your right is an Afterlife only accessible door. Go through it, jump a bit, then electrocute the voltage meter. Make sure you put HD.

This is my own video achievement guide that I made recently.

This is by far the easiest achievement to obtain in the Uprising DLC and you might even get it on accident.

Please watch the video as I give a complete guide on how to do this achievement!
If you have any questions please ask! Thanks :D

Tip:
Use the Double Points at the very beginning when you spawn to get 1000 points as fast as possible!

Probably one of the easy zombie achievements to get. Here is a quick video on how to obtain this on solo as quick as possible.

My guide to this achievement. Short. Sweet. Hope you guys enjoy. 25 words long are you joking me? that's not short or sweet. :(

ARG. COME. ON!. xD