Note: For some this has been glitchy. To make sure that this doesn't happen to you play through the campaign in single-player and do not go into Sandbox mode while you're playing through the game for this achievement, as some have reported drinking in Sandbox has affected the achievement, as well as co-op partners drinking alcohol has cost them the achievement.
For this achievement orange juice is your best friend. You have to play though the campaign as you need the cutscene to appear at the end of the first 72 hours for the achievement to pop.
- Always carry at least 4 orange juice, ideally half your inventory should be health.
- Be a high level, the more inventory slots the easier this is.
- Wear the ninja costume, it allows you to move through zombies with stealth.
- You can consume any juice so have some quick step/ painkiller ready, especially during the fight with the Twins.
- Only consume orange juice, fruit, soda and snacks, nothing else.
You will get the achievement when the military arrives in Case 7-1.