Fastest Way To Delete Large SAP Client

1) Look for the biggest tables in your system, usually tables with custom data in it.
2) Find those tables that have different mandants (clients)
3) Block the client you want to delete for access by normal users
4) Use  SQL commands to remove the data from those big tables BUT use
WHERE MANDT =3D nnn statement!!!
5) once you have reduced the size of the client enough you can do the normal client delete.