A script is available in rescue mode for mounting the partitions of the disks. It only requires to type the following:
sudo mountall.sh
The partitions are then available in the directory /mnt.
A directory corresponding to each partition has been created.
This means you find the partition /dev/sda1 mounted in /mnt/sda1.
You may see some errors when running the script, as it tries to mount the SWAP partition.
This is normal and you can simply ignore it.
We have prepared to tutorials for mounting the disk in special cases: