Call of Duty Deluxe Edition Box Set Cheats for PC
Play united offensive, go to noville, fight in the mansion and destroy the first 3-4 tanks or wait until the childs room wall is blown out thea jump onto the wall below (it's only about a foot high) you should see that your about 5 feet off the ground, then walk forward and stay on the wall and vwola your out of the map. Its a little hard but it works.
P.s. The only way to get back in the map is to walk all the way to the bottom of the street you started on