Get into Tony Hawk AMJAM
Entrance to the skatepark is close to last completed mission. Talk to the judge standing next to the halfpipe. Do 2 combos to sign up to a contest.
Pay the fee and get sponsored
You must pay the judge the entrance fee. The contests is like this: every 30 seconds a skater with the lowest score comes off. If you win the contest, go back to the skate ranch.