COD BO2 Tranzit Tower Of Bubble is the main Easter egg on this map. Its has two side, Richtofen and Maxis. Both has a different procedure. Samuel ( one of the character on this map ) is the one who will hear the voice of Richtofen ( giving instruction on what to do ). Four players are required.
Step One : Turning on the power
To turn on the power, you have to go on the third bus stop which is called Power Room or Power Station. There are Three parts that has to be build, Zombie hand, Lever and Power Board. All of this parts can be found inside the White Room. If you cant find it, i have a link to point all those locations.
Step Two : Navcard Reader
Navcard Reader contains four parts ( Meteor Rock, Power Box, Radio Transmitter, and Board ). Meteor Rock Location : is on the Bus stop ( Starting Room ) Beside the Mystery Box. Power Box First Location : Farm, Between the refrigerator and exit door. Its on the wall. Second Location : Town, Its on the metal garbage and Mystery box. Radio Transmitter Location : Its on the other side of the Tower, Theres a building ( Natch Der Toten ) and look on the top of the shelving or on the drawers the is laying down. Board Location First location : On tunnel where you get the Jet Engine, Its on the hall way. Second Location : Power Room, Its on the next building on the second level. Look on the corner or on the top of it.
Step Three : Jet Gun
Thrustodyne Aeronautics Model 23 ( Jet Gun ) is a Wonder Weapon and one of the main buildables in this map. It contains four parts ( Jet Engine, Handle, Wire and Gauge ). All of this parts are scattered around the map. Check this link for all the locations.
Step Four : Powering up
Get the Jet Gun and bring it to the tower. Tower is located at the corn field, left side. Its between Farm and Power Station. Once you are under the tower, use this Wonder Weapon to power up the table.
Step Five : Kill Zombies under the Tower
On this step richtofen wants us to use like a RPG, Grenade, etc. or Mustang and Sally ( best option ). Train zombies under the tower and use one of your prepared option. This will take 1 to 2 rounds. If you done this correctly, richtofen will say its too much power and need to reduce it.
Step Six : Reduce the Power
To reduce the power, all four players must have EMP grenade. Each player must go on the different Light post and create a teleporter tunnel. Then all four players must throw EMP at the same time. If you did this correctly, You will see a green light coming out on the light post. Congratulation, you unlock the achievement.