Registration problem

<p>I have registered for June SAT II(Math I, Math II, and Physics)
So, now I want to change Math I to Chemistry. I tried to change but it wrote that "no need to change". What I should do?</p>

<p>Don’t worry about it. During test day, you can take any subject you want, regardless of the one you signed up for.</p>

<p>Really? Thanks!</p>