Step by step tutorial :

1. Create a custom lobby and set the party to open and player limit as 4
2. Have your Friend make the EXACT same custom lobby in his own party
3. Leave your own game and hover over Public match
4. Click Triangle to open your friends list
5. Hover over your friends name then hit square to join and as soon as you hit square hit x as Fast as you can and don't stop until you are in the lobby.
6.To get in the lobby do step 5 but your friend will have to leave the lobby as soon as he sees your name. (This has to be done EXTREMELY fast)
7.If done correctly you will take over your friends lobby and the game will automatically start.
8. For you to get the XP to count on your account, once you are finished the custom game you must join a multiplayer match and get at least a few kills and few deaths before you sign out.
9. do this and when you sign back in your custom game will have counted

Will be hosting soon so message for invite and please thank topic guys helps alot!