Instructions
Run to the far southeast corner of Bourgogne. If you look at your map, you will notice a small bulge on the map that juts out towards the sea -- this is where you need to go.
Head inland from the coast and look for an abandoned German base. You will see a missile silo and the ruins of a destroyed house.
Approach the destroyed house and you will find an abandoned Wulf tank embedded in its walls.
Jump on top of the tank and hit the "Y" button to enter the hatch.