Send listserv@listserv.uga.edu the command:

delete name-of-your-list userid@node

You may delete multiple subscribers in one email message to Listserv: just put each add command on a separate line.

If you wish to supress Listserv's normal message to subscribers, preceed the delete command with the quiet option.
For example,
quiet delete mylist jdoe@uga.edu

Use Manage Lists/Manage Subscribers