You can change delivery instructions only up to 60 mins before the delivery slot time.

To change delivery instructions for all your meals:

1. From the Home tab, tap the profile icon on the to right corner
2. Go to Active Packs / Subscriptions
3. Pick your active pack
4. Below the address, tap and change delivery instructions as needed

To change delivery instructions for a specific meal:

1. From the Home tab, tap the profile icon on the to right corner
2. Go to Active Packs / Subscriptions
3. Pick your active pack
4. Pick the meal in question
5. Below the address, tap and change delivery instructions as needed