Like past games in the series, Call of Duty: WW2's Nazi Zombies mode lets players upgrade their weapons using a Pack-A-Punch device. And as returning fans may expect, reaching the Pack-A-Punch in Call of Duty: WW2 is not straightforward, and has some steps that need completed before players can access it.

To find the Pack-A-Punch, or Weapon Upgrade Station, on Call of Duty: WW2's The Final Reich map, the first step is switching on the power. As anyone that has attempted the elaborate Easter Egg or built the Tesla Gun already know, turning on the power is not as easy as just finding the switch. Firstly, players need to turn on all three valves to power the generator in town, which can then be used to blow a hole in its center.

The explosion will result in some rather gruesome flaming zombies, but they are easily disposed of. After killing them, drop down into the hole, turn the power on, and then head to the Command Room. The next step is switching on the two power generators, which will grant access to the Salt Mine and the Emperor's Chamber, as well as three disposal tubes.

Call of Duty: WW2 Zombies - How to Pack A Punch - Zombies Pack A Punch

There is one generator in the Lab and one in the Morgue. Once both are powered on, players can use the trash disposal tubes to quickly travel to the Weapon Upgrade Station/Pack-A-Punch. There is one tube in the Lab, one at the Tower, and one in the Command Room. The tubes have shining gold lids, so they're easy to spot before opening them up.

Sliding down a tube costs 250 Jolts - the equivalent of points in Call of Duty: WW2's Nazi Zombies mode. After the short tube ride, simply hit the button at each gate. Once all the tube gates are raised, the gate surrounding the Weapon Upgrade Station will also rise, allowing players to upgrade their weapons for 5,000 Jolts apiece.

Veteran Zombies players will know to wait until higher rounds to Pack-A-Punch their weapons. It's also smart to use the Weapon Upgrade Station on empty guns so players can refill ammo without having to wait for a Max Ammo. With these tips in mind, Call of Duty: WW2 players should be able to find the Pack-A-Punch and use it strategically to help them reach higher rounds in Nazi Zombies.

Call of Duty: WW2 is out now for PC, PS4, and Xbox One.