How will remove all expired role assignments to number of users ?

To remove only 1 single expired role:

1. Go to SU10 > Click on Authorization Data > put * in option.  

2. "Users" > Go to Role Tab & select option button "remove" & mention name of roles with its corresponding expired validity "From" & "to" date

3. Then Click on "Save" once its starts excuting it will check the mention roles

4. Entries with validity dates against every user in list & where the entry matches will remove that role from that corresponding user master record. 

5. On the other hand if you select option "Add" will add the mention role with its validity date to all listed users.