Deleting old users in the "managing users" screen

I am an administrator for my CSI.  I need to delete some old users, and change some privileges of others.  But when i clockon the user and scroll down to the bottom, i only see their name and address info - nowhere to change their privileges or delete them.  It feels like something is wrong - i should be able to change their privileges at least in there.  Right?  Thanks for the help.