recover hosts hostname names | mount -o remount,rw /

1. Boot into recovery mode with steps from here: How do I boot into recovery mode?
   Steps 2 - 5 below are from the above question.
2. Hold Shift after your BIOS has passed, then choose:
   "Advanced options → something ending with '(recovery mode)'"
3. Choose the "Drop to root shell prompt" option
4. Remount the root partition as R/W with this command:

   mount -o remount,rw /
   

5. If you have separate partitions, execute this command to mount them:

   mount -a
   

6. Edit the /etc/hosts file with this command :

   nano /etc/hosts  # Replace `nano` with your favourite command line editor
   

7. Make the changes you want.
8. Press these keys to save and exit it: Ctrl+X; Y; Enter
   Note: If there's a + between two keys, press those at the same time. If there's a ; between two key sequences, press the first sequence, then release it, then press the second.
9. Reboot:

   reboot