The people who are wanting to use this in Linux Mint Cinnnamon 20. first you must install lightdm-gtk-greeter and its settings by this command sudo apt install lightdm-gtk-greeter lightdm-gtk-greeter-settings Next, you have to download the theme and extract it in the Downloads folder. then run this command to the theme to the /usr/share/themes folder sudo mv ~/Downloads/ /usr/share/themes Next, you have to open LightDM GTK+ Greeter settings by searching it in the menu and open it with your password. Then you can choose the gtk+ theme from there and save your configuration. Next we have to create a configuration to tell lightdm to use the greeter that we are going to specify. To do that I will be using nano as my editor. Run the command: sudo nano /etc/lightdm/lightdm.config then paste the following line [SeatDefaults] greeter-session=lightdm-gtk-greeter then save the file and exit nano. After that you can check of lighdm is using our specified greeter by running this command: lightdm --show-config If you see greeter-session=lightdm-gtk-greeter, the you are all fine. Then run the following command to restart lighdm so as to see the login screen: sudo service lightdm restart Then you should get the login screen with you theme.

How do I install this?