Reclaiming Acrobat Professional 2017 licenses

Hello,

We have a TLP volume license for Acrobat Professional 17 and have Acrobat installed on 10 computers.  A user has left the company, so I want to ensure that the Acrobat Professional 17 license can be reclaimed for use later. 

1) What is the process for this if I have access to the computer?   

2) What is the process if I no longer have access to that computer?

Thanks,

Andrew