How to add a role to a user in SAP?

How to  add  a role   to a user in SAP?

Enter the  tcode SU01  in the command filed ,  press enter the  user maintenance  initial screen will open,   select the desired user from the  drop down list, then press change  button

User maintenance window  will open,  click on the  role tab,  Select the desired role  to add  from the drop down list and press the save button.