Go to this site: http://kc.mcafee.com
Search for 'vpn' in the Ask box there.
Click 'Firewall Enterprise' on the left-hand side.
Browse through the articles there to find one you can use.
Many, many times there have been links to KB articles posted in this forum for specifically what you are asking for. Search these forums to find those links.
This forum thread may be also be good source of information:-
and this one come to think of it:-