Can't delete old backups from My Book

I’ve seem this topic brought up sporadically with other drives. There seems to be no easy way to delete older backups using the WD Backup software. My 4T drive is full and there have to be multiple backups on it but there is no easy way to see them and delete older ones. I’ve seen the comment to go into the …swstor… file and “delete old backups” as if that’s intuitively easy. It isn’t!

Any suggestions?