People are seeming to have issues with this so im gonna lay it out here.




Subscribe to the Mod on Steam Workshop

Launch MCC in Anti Cheat Disabled (Launch through steam to show the option, if you launch through a shortcut, most likely it will launch the EAC Version, which will not work.)

Navigate to Create, Halo 3, Forge, Then Modded Maps

If you did it correctly, the Battlefront Maps will be there.




Troubleshooting

Didnt see 'Modded Maps'?
Either you didnt launch with Anti Cheat Off or its bugged, try relaunching.

Didnt see any Battlefront Maps?
Make sure your subscribed, sometimes, if you just subscribed to a mod, the game wont have time to validate the files to accommodate for the new changes, try relaunching and waiting for validation.

If you have any further questions, leave it in the thread below, or look up a Youtube Tutorial, there are plently online.