Migrating users from DDVE Version 6.2 to 7.7

Looking to migrate users from Data Domain Virtual Edition version 6.2 to 7.7 .   What is the best way to redirect the customer\client that are running avamar to point to the new DDVE 7.7 server.       Can I install a new server running 7.7 and just repoint my clients ?  if I do that,  would I not be able to run restores from the 6.2 any longer  ?   or is there a way to migrate al lthe data , import,  from 6.2 yo 7.7  ? easliy  ?