How to Get Into the Pack a Punch in Call of Duty: Zombies for the iPod

Use your knife in the first three rounds, to save ammo and build up more points. You should be approaching 3,000 points at this point. To maximize points further, fire a few pistol shots at the zombies before using the knife; however, keep an eye on your ammo levels.

Open the the door that costs 750 points, then the following one that also costs 750. Spread this around the team rather than one player taking the whole cost of the doors. Buy the Thompson, which is a powerful weapon for this point in the game. Continue fighting off the zombies and scoring more points until you reach round six.

Open the stairs and move your team up, then use the Mystery Box to try to get a better weapon. If you have the Thompson, switch to your pistol before taking the weapon that the Box offers -- that way you won't be left with a poor weapon should the Thompson run out of ammo.

Open the debris, and drop down from the upstairs room. Turn on the electricity here. This is a good place to group your team and establish a perimeter while you fight off the zombies and build your points.

Venture out to the teleporter rooms. You have to activate each one from their own room, then get back to the starting point of the level within 30 seconds to link the teleporter to the mainframe. Either run back yourself, or have a teammate standing by at the mainframe. Teleporter A is located in the south east corner of the map, teleporter B is in the middle of the north-most edge of the map and teleporter C is the furthest away, on the west edge of the map.

Return to the mainframe. Each time you activated a teleporter the door to the Pack-a-Punch opened a little more; now it is fully opened. Approach the "Pack-a-Punch" and pay the 5,000 points to get the weapon upgrade.