Text tutorial:

Create a new playlist, add 3 races to it then save.
Go to my playlists and select it, once that's done press triangle, circle and l1 in order then go to the interaction menu and kill yourself. when that's done just press start go to options>online and disable passive mode, be sure not to disable it from the interaction menu or it will not work.

After the 10 seconds are up you are now in god mode, enjoy.