I have N360 Backups on External Hard Drives. One BU using 1.6 TB. How do I restore files?

I have N360 Backups on External Hard Drives.  One N360 BU is using 1.6 TB.   I see the ARestore Application (Norton).  I have used that Application but only 153 GB restore.    How do I restore the remaining?   They are not Compressed, Zipped...but the file names are just a buch of letters & numbers I cannot open.  HELP