Few a years ago i bought the  garmin 1000 but  I don't have the  key anymore. How do i go about retrieving it ? Is it possible to install the gauge in the carenado tbm850 ? Thanks

Contact via support email with your purchase information (email used, name, etc) and someone will try to locate it for you.

 

I don't know if it's possible at all and not about to purchase the Carenado aircraft to try.  Typically Carenado creates their aircraft so it's rather difficult to modify the avionics.