Enter during a game.
While in the main single player menu, goto my character, hold left or right on the D-Pad, and then use the white button to select different characters, including pros.
Go to "My Character", then hold LEFT ANALOG-STICK Left while tapping Y. This will change your character to any pro of your choice. Pro players must be "unlocked" for this to work.
Ok go to a bunker on your knees and snap up and hold L. Then press down on the D-Pad and walk straight forward into the bunker then while still holding L. Just keep walking forward and holding L and you will shoot paintballs out of your head.
To skip straight to the final round of any tournament, excluded the first, simply beat the first and instead of playing the new tournament, play the first til you reach the final round of it. Once it shows you the bracket click A and instead of pressing A to start hit B and play the newest tournament. You should be put in the final round.