Replaced Old Passport Slim 1TB with new 2TB Portable; but Backup/Restore tabs greyed-out!

I am technically pretty poor and thought replacing my old 1TB Passport Slim (getting full) with a new 2TB Passport Portable would be quite straightforward. I followed all the download links with WD Discovery, but the previous Slim Backup/Recovery screen is still active, but does not allow me to set backups; the Backup/Recover tabs are darkened/unresponsive. There does not appear to be a new Discovery screen that allows me to set my backups. There was no instruction to uninstall the Slim WD Smartware before downloading WD Discovery. I would be grateful for any advice on what I have done wrong. Many thanks