i was needing to do this today too.
i didn't find a solution on th eforums, but you can do this 'by hand'...
edit your db:
table: datastore
title: maxloggedin
and very carefully edit it to what you want.
in the below example, it's set to 476 as the max users:
Code:
a:2:{s:9:"maxonline";i:476;s:13:"maxonlinedate";i:1115584170;}
in the below example, it's set to 7 users:
Code:
a:2:{s:9:"maxonline";i:7;s:13:"maxonlinedate";i:1115584170;}
i didn't mess w/ the maxonlinedate... i just set that number to 4 and it was quickly updated as there were 7 members online at that moment.
HTH!