I wish to intercept traffic from the client to a server and decrypt it.

The messages are encrypted (keys are setup via kerberos KR5).

To do the decryption, I would need the servers long term key (the long
term key that is stored in and maintained by the kerberos key
distribution center KDC).

On windows server operating systems, how can I get a server's (say file
server's) long term key from the KDC (domain controller)?

Obviously I am assuming I have admin access to the domain controller...