It's good, quite long though, but then you are working at Cmd prompt level. Powershell would be my preference, you can invoke sql cmds just as easily via PS.

If i'm critical it's due to the references to old system catalogs and procs.

Sys.master_files and sys.database_files replace the old database catalog info, also get used to using ALTER USER WITH LOGIN rather than sp_change_users_login.