How to extract files from unallocated space

First run blkls from Sleuthkit, which copies the content of unallocated data blocks into folders for each file type.

blkls <image.E01> > image.blkls

Then run Foremost as the data carving tool, to look for file structures (headers, footers, magic bytes etc) in the image you made with blkls:

foremost -q -b 4096 -o <output directory> -c /usr/local/etc/foremost.conf image.blkls