Requirements, must have 2 controllers and must know someone that owns the season pass and Is willing to let you borrow their account.

1. Sign Into the account with the season pass on your first controller
2. Sign Into the account getting the map pack onto the second controller
3. Load up Ghosts then proceed to multiplayer
4. With the first controller go to the In game store and download the season pass (Should be free)
5. Once downloaded with the first controller look at the map packs, they should be checked and be $0.00
6. Back out of the store, now with the second controller go to the store
7. The map packs should cost $0.00 and you can then add them to your download history for free, this does NOT require a license transfer just an account with the season pass, do NOT try to license transfer from someone who has done this It will not work you must follow this tutorial exactly how It Is written to get the maps to work under your account

I just did this for Invasion so It should work for everyone, now this may not be for everyone but for the Devastation map pack I have to clear my system cache 5-10 times to use It, If the Devastation map pack, or any map pack, disappear and you can't use them go clear your system cache 5-10 times then try again.

Side note, this works with 3 of the 4 map packs I sincerely doubt It will be patched and will probably still work after the 4th dlc so If you know a guy who Is willing to let you do this glitch you can get all 4 packs for free

Update 1: If clearing the system cache doesn't work and you can't play the maps go and delete both compatibility packs and the title update, then clear the cache for all storage units you have, then re-download both compatibility packs and the title update In game (Not from download history), the maps should now work but restart your console to be sure

Update 2: It seems that If you are to sign out and sign back In on Ghosts the maps will disappear, they return once you go to the dashboard and come back on to Ghosts, note that If for whatever reason you need to sign out of the account on Ghosts the maps will not disappear until you sign back In to the account, so If you are signing Into another account the maps will still work until you sign back Into the account you did this glitch on

Note: I can not provide an account with the season pass so please don't ask me, I also can not license transfer you the maps as stated above that does not work, also please try to not ask for someone to let you borrow an account with the season pass/license transfer on here I would rather not have the post be deleted, thank you. Also If you are having trouble getting the maps to work and do find a way to get them working let me know by posting It on here or PM'ing me, I will then update the post so people know what to try