You’ve got the first part:
1)
fdisk -l /path/to/image
to find the start offset. Take that number, multiply by 512, and you’ll get the offset option to mount. So, for sda1 in your case, 5 * 512 = 2560. Then run the mount:
mount -o loop,offset=2560 -t auto /path/to/image.dd /mount/point
Update. Actuall this way will work for both mbr and gpt drives:
—- or in case of bigger than 2tb drives. Read 1.1) —–
1.1)parted /path/to/image
must set Bytes instead of cylinders : unit B
print
lets say start is 1048576, then this should be an offset to be specified.