Becoming a Character

Hey, i'm a huge gravity falls fan and i'm not quite sure who to contact about this so i figured it wouldn't hurt to place my dilemma here. I am interested in becoming a chacter from this website considering there are some that still aren't taken. it says i have to contact someone before choosing a character that isn't an oc so i guess this is what i'm kinda doing here. i would appreciate it if someone would respond and help me out. and if it makes any difference the character i am interested in is wendy. so yeah, if someone can help this helpless noob i'd really appreciate it, sorry for the long lecture.