> I understand the process to move a list from one server to another server
> using the GET and PUT commands on the headers, but what exactly has to be
> done to migrate all the users for that list as well?

The easiest way is just to move all the  listname.list files to the new
server. If it's not local or you can't FTP them, then you need to:

GET listname LIST
PUTALL listname LIST

This command allows you to PUT an entire list file, that is, the list
header followed by the list of subscribers.

Caution is needed here as the column width is 100+ for subscriber data.
Any wrapping that your mail client might do with the PUTALL would corrupt
this information. Also note: PUTALL does NOT work with DBMS lists; only
the header information is replaced.

The only other way is to REView your lists, then do a bulk upload on the
new server. The problem with this method is you will lose their settings
(other than list defaults) they may have set since subscription.