1. Get the 3 parts for the launch machine by unlocking 3 perks (the perk unlock sequence starts on round 3 and happens every 3-4 rounds after that) (you can do steps 3 - 5 simultaneously)

2. Insert the parts on the launch pad in the Supply Depot area (north side of the map)

3. Call for an evac near the launch pad, on a bench with radios on it (you have to stand in place while it is progressing)

4. Wait 3 rounds, after which you will hear a horn sound cue and see a Zeppelin airship approach in the sky. Once it stops moving, you can request its hatch to be opened at the same place that you requested the evac. You will have to do the same process as the evac once again.

5. Grab a fuel cannister from near the fountain at the Bunker Underpass (middle of the map, it can spawn in different locations inside this area)

6. Use your fuel cannister on the generator in the Generator Yard (this acts as power for a short period of time)

7. Shoot the 4 red parts on the Zeppelin in the sky to de-obstruct the launch path (they will explode if you're doing it right)

8. Stand on the launch pad in the Supply Depot area and activate it to get to Pack-a-Punch