Transferring from ChemEng into Grainger

I applied to UIUC this fall and I applied with my primary major as Chemical engineering but I am nowhere near decided on ChemEng and I want to know if it's difficult to transfer to Grainger, because for some reason Chemical Engineering is the only engineering major in the liberal arts and sciences school? I would greatly appreciate help as I'm already reconsidering if I want to do ChemEng or something else like Aerospace or Mechanical Engineering.