hi, i needed to know some information regarding re-applying for usmle step 1 as i cancelled my exam coz i wasn't sure i would pass it.can you tell me what is the procedure??

If you are in your eligibility period just reschedule with Prometric for a fee that varies from %50 to $105, depending how many days ahead you cancelled. You can extend your eligibility period just once for a $65 fee in the OASIS ECFMG website. If you want to move the eligibility once again, you must fill again an on-line application and pay $820 Let's say your period was Oct-Nov-Dec, you paid $65 to move it to Jan-Feb-March. If you want to move it to April-May-June, you have to pay $820 and fill the application again.
I already called them because I want to have my bases covered, since my period finish at the end of March, my test is on March 28. If I feel not enough prepared I have to pay $820