Well I cant really show you the steps on video, so heres a text tut.
Since I'm in Australia its extremely hard to find a good connection game, so I stumbled upon a theory in my head that actually worked for me because im also capped.

1.) Go to the Dashboard and change your local country to like Africa or somewhere where no one really plays the GOW3 Beta.
2.) Make sure you have a laggy connection or just really get lucky.
3.) Find a game of whatever mode you want (TDM, KOTH, CTL) and play it.
4.) If lucky enough, you should be playing against a crap load of bots, actually
a game full of bots, they should all have asterisks next to their name.
5.) Stay in the game for as long as you wish till you reached your desired level or challenge.

This was found by me so I would really appreciate feedback if this worked for you also.