The SMC tool lets you add users to existing roles and grant RBAC rights to existing users. (An RBAC right is managed in the portion of the SMC tool.)
Change to the location of the SMC invocation command by typing the following:
# cd /usr/sbin
Start SMC by typing the following command:
Double-click on "This Computer" (or single-click the expand/compress icon next to it) in the left-hand Navigation panel to expand the tree beneath it. Do the same for "System Configuration", and you will see the Users icon underneath.
Click on the Users icon to start the application.
For more information on the , see the man page smc(1M).