1. Start Campaign: Launch the campaign mode and proceed to the second mission, "The Island".

2. Find Hidden Path: In "The Island", locate a hidden path to the left of a destroyed bridge, leading into a riverbed.

3. Follow the Riverbed: Navigate downstream until you find an abandoned tank hidden in foliage.

4. Enter the Tank: Interact with the tank to get inside and activate the radio found on its control panel.

5. Activate Easter Egg: Listen to the Morse code messages played by the radio, then exit the tank.

6. Witness the Display: Look up to the sky to see a unique aerial display, marking the Easter egg's activation.