This one is a grind, Online with this game has been DOA and I doubt it's going to get any better. For this you need to get 5000 online points and you will get them 4 per win, so the grand total is 1250 wins. The only thing I'm not sure of is what happens if there are more players since I've only been able to get up a single other player at the moment.
Another problem is that as you play raked matches, it's not saving. I've run into a problem where I'll get a good amount of these points and then I'd turn the game off or the game just decides to crash and the points I've made are lost. The best way to help with this go into back into the sound options and make an adjustment. This will make the game save and this game crashes a lot, so get used to it.
Well, it seems there's a extra trick where if you are the host of your match and the other players log out of it the game will double your points. It can cut the matches down by half.