To assume a role, use the su command. You cannot log in to a role. For example:
%su my-role Password: my-role-password # |
To use commands in the profile, simply type into a shell. For example:
# lpadmin -p myprinter options |
The lpadmin command is executed with any process attributes, special UIDs or GIDs, that have been assigned to the lpadmin command in profiles for the role assumed.