delete user and user rights under 2000 server

Hello,

I work on a 2000 server, sp3

I have added 3 users account. I have also give them
some "user rights
assignement" : act as a service.


I have to delete those 3 users, but, i think that if i do
that, when i would go
in the "Local security policy / local policies / user
rights assignement", and
"act as a service", i would have some old key,
corresponding to the 3 deleted
users.


So, i went in "Local security policy / local policies /
user rights
assignement", and "act as a service", but, in this box,
there is no way to
remove the users !

Why ? is there a way to avoid that ? and to properly
delete user and user
rights ?


Thanks