Unfortunately, Aerosoft does not have control over PFPX license keys and as such only, the developers of PFPX can reset your serial key. You can reach them by submitting a ticket on their website: http://flightsimsoft.com/support/ Please make sure to include your offline activation information, as well as a small explanation of why you have exceeded your activation limit.
Support article
Invalid or Blocked PFPX serial keys
