Restoring Grub2, Ubuntu Unleashed Book

While running Lubuntu from a Live CD
sudo fdisk -l
shows me
Device     Boot      Start        End    Sectors   Size Id Type
/dev/sda1  *          2048 1808337985 1808335938 862.3G 83 Linux
/dev/sda2       1808338942 1953523711  145184770  69.2G  5 Extended
/dev/sda5       1808338944 1847399490   39060547  18.6G 83 Linux
/dev/sda6       1847402496 1953523711  106121216  50.6G 82 Linux swap / Solaris

and

sudo blkid
/dev/sda1: UUID="32730290-3726-43d4-b7c0-0d0fe62946c8" TYPE="ext4" PARTUUID="0002d4c2-01"
/dev/sda5: UUID="fed80f39-139e-4fc2-8767-3feaa5e98d86" TYPE="ext4" PARTUUID="0002d4c2-05"
/dev/sr0: UUID="2016-07-20-12-16-02-00" LABEL="Lubuntu 16.04.1 LTS amd64" TYPE="iso9660" PTUUID="473bb8b2" PTTYPE="dos"
/dev/loop0: TYPE="squashfs"
/dev/sda6: UUID="4241ce6d-a454-48ac-8e60-a6cba2023f05" TYPE="swap" PARTUUID="0002d4c2-06"
/dev/zram0: UUID="e5831334-c728-44ab-a16e-8503712fe29f" TYPE="swap"
/dev/zram1: UUID="93379eba-1068-499a-ad02-ce80abcc9262" TYPE="swap"
/dev/zram2: UUID="82b4b299-ada7-44eb-a84d-d36c5b4dd78d" TYPE="swap"
/dev/zram3: UUID="957fb072-1ddd-4037-a592-8b0edc5678f0" TYPE="swap"

$ sudo mount /dev/sda5/ /mnt
mount: special device /dev/sda5/ does not exist (a path prefix is not a directory)