Hard Drive Failure - Problems Restoring from External Hard Drive using DBAR

The hard drive on my Dell Inspiron 15z Laptop (2.5 years old!) has just failed and been replaced by local firm. Prior to failure I had upgraded from Windows 8 to Windows 10, and as recommended carried out a full data and system backup to an external Hard Drive using Dell Backup And Recovery. Now that my Laptop is working again I'm trying to use the backup to restore my data but unable to figure out how to access the information on the external drive using DBAR. Does anyone know how I do this please? Thanks. Tony.