A user inherits roles from all groups to which the user belongs. You can also assign
roles directly to a user. Whenever a user is assigned a new role, it only takes affect after
logging in with a new session.
Role required: user_admin or admin
You cannot delete roles that are assigned to the group from the user record. You
must remove the user from the group record.
and then open a user record.
In the Roles related list, click
In the Collection list, select the desired roles, and
then click Add.