Changing SAT IIs

<p>I was wondering if anyone knew if it's possible to change your subject tests once you've registered. I registered to take the Math 1 test in May but now I want to take the Math 2 instead. I'd be taking it on the same day and at the same test center, just taking a different test. Does anyone know is this is possible, and where to call to make the change?
Thanks!</p>

<p>You don’t have to decide which test to take, or how many, until you show up. The test booklets contains all of the tests. You pick one. If you want to take two instead of one, they will bill you later for the difference.</p>