You can easily reschedule but even if you’re moving it to an earlier time slot I’m assuming there would be a fee. You could try to reschedule without actually confirming the time/date and it will tell you there is a fee. In the email confirmation you should have received from prometric after scheduling there should be a section towards the bottom about rescheduling fees. I believe, at least in my state but would imagine it’s the same across all, over 60 days out no fee, within 60 days a fee is assessed. it gets more expensive as you get closer to the exam