I want to alter my registration

Test Preparation
1

<p>i registered SAT1 in oct and SAT2 in nov.but i was getting nervous on my SAT1 so i decided to reschedule this plan.i want to take SAT2 at oct and 1 in Nov.The deadline of changing is Sep.22nd.Anybody tell me what should I do on Collegeboard?Cancel the former one and re-register or wait till Monday to call to change the type?Help!</p>