Have you read the Prosys manual that is available online? It covers how to connect a computer and upload the settings. The connection may differ depending on whether the Prosys is part of a larger IQ network or not.
FWIW, the Prosys is essentially The Crown IQ-USM 810 that became a BSS product when Harman bought both Crown and BSS, as BSS is the DSPline within Harman's world. That explains it being an IQ device.
Is this your system or are you trying to access someone else's system to make changes? Some people are understandably hesitant to let others go in and mess with their house processing. This hesitancy might be increased if the person wanting access is not trained or certified for the gear. I can't speak to what, if any, security is incorporated in the current programming, that may or may not be an issue.