Re-install? Reactivate?

[RWB]

Since i bought my EFI eXpress 4.5.5 back in Nov 2014 i've had little opportunity to use it. Largely because, after that date i had to get extensive repairs done to my MacBook Pro (OSX Lion 7.3), including a new logic board.
Subsequently, as a novice to Fiery anyway, i have come adrift from little knowledge i had about using my still new rip.
I am now in a position to resume normal usage. I have placed my dongle directly into the MBP but alas, cannot get it to print from inDesign - or even re-print from the 'Printed' list one of the test prints i made back when i originally installed - even though the dongle still shows a red light.
Under the terms of my licence would it be possible to uninstall and reinstall - going from scratch? Is that possible?
Many thanks for any help and advice you can give me.
Best wishes, Richard (RWB)