Completing these challenges can only be done by the custom character the player builds at the very beginning of the game. This is also the same way to unlock Jack Black's playable character, Officier Dick. The player will also be rewarded with 2000 EXP for completing all of the Create-A-Skate challenges. It may take a while, but completing all of these challenges is part of the game. Completing them is essential for getting 100%.