Ok here's what you got to do. You know those towers that are around the edge of the map on sandtrap that you can't get to, well those are the key to getting the golden warthog.
Step1: go to the map sandtrap.
Step2: get a warthog and get a friend to get in and then float the warthog over the outer sand the guardians can't kill you friend in the warthog and so they get mad and from the closest tower a laser will shoot from it and kill you friend.
Step3: do this at each tower and after you have done this at each tower close to the last tower there will be sitting you golden warthog.
Step4: get in your warthog and have fun with it.
Step1: go to the map sandtrap.
Step2: get a warthog and get a friend to get in and then float the warthog over the outer sand the guardians can't kill you friend in the warthog and so they get mad and from the closest tower a laser will shoot from it and kill you friend.
Step3: do this at each tower and after you have done this at each tower close to the last tower there will be sitting you golden warthog.
Step4: get in your warthog and have fun with it.