How do I invoke the qmail-users Mechanism ??

[Tony D'Andrade]

Hi. I dont understand how to invoke the qmail-users system.  I have a
server and /var/qmail/users/ is empty.  I would like to be able to use
the "assign" mechanism.  How do i do this ?   I tried to run qmail-pw2u
but it just seems to hang forever.  This is how it says to do it in 
Life with Qmail. Also if i start using 'assign' will it somehow mess up my 
exisiting config ?  Does qmail have to be restarted as well ??

thanks in advance !
tony