Switching from BME to ChemE?

I was admitted into UCI as a biomedical engineering major (1st choice major), but after doing a bit of research I’m leaning more toward chemical engineering now. How easy is it to switch between engineering majors/would I be able to do it towards the beginning of the year or would I have to wait until the end of my freshman year?

Here is the link on switching majors. You need to meet the GPA requirement and finish some required courses before transferring. You can map out your courses during the Freshman orientation with your advisor.

http://www.changeofmajor.uci.edu/CoM_Engr.html