This is how you disable the password login for Linux Mint 18.3
Open Terminal and use this command:
sudo nano /etc/lightdm/lightdm.conf
and change this line from you user to false like this:
autologin-user=false
save it and on bootup no more password needed 🙂
So everything will look like this:
autologin-guest=false autologin-user-timeout=0 autologin-enable=true autologin-user=false allow-guest=false
Well I found an easier way 🙂 mind you I am just starting using Linux Mint lol anyways Click on Menu Than click on System Settings and look for Login Window or just type Login Window on the search box and it will come up 🙂 than this pops up. Click on the Users tab.
As you can see you can type in the box where it says username false to enable the password login or the username to enable auto login for that user 🙂