Rescheduling the Step 1

Whats up with rescheduling the step 1? unfortunately for me some unforeseen circumstances have come up and I wanted to take the exam in 1st week of Feb but seems like i will be pressed for time (personal matters)....I wanted to know where can I get the info of how much I would have to pay extra to reschedule the exam and whether that would show on my record? and how long before the exam can I reschedule? b/c of personal problems if I'm not available to take it I would like to reschedule it (b/c i'll probably have to go out of the country).....besides this exam basically defines us IMGs..

any quick help on this matter would be appreciated!

guys, you have all been a tremendous help in the most stressful of times, so I would like to whole heartedly thank you!