All Voicemail admin is done through Feature 983 if you don't have the right password I can tell you how to reset the password.
Once your in goto mbox etc.
A Feature 986 is Transfer to Mailbox and has nothing to do with setting them up.
The basic Features for Norstar Vm are
F980 - Leave a Message to another users VM
F981 - Open a Mailbox
F982 - Operator - sets Operator avail. bus. open etc.
F983 - Admin
F986 - Transfer to Mailbox

Let us know if this helps or you have further questions.