change the login window

1. first open the folder / usr / share / gdm / themes
2. select an existing folder, then copy.
3. if so, paste the folder that you want to place.
4. after that, open the folder that you'd paste. then right click and click open terminal.
5. write in terminal sudo gedit write a xml file of type then hit enter.
6. after that replace the jpg files with the jpg files you choose.
7. after that save
8. right click on the folder and select copied arcive Creat .. name the file as you please change the tar.gz file and then save.
9. after that open the login window, and drag files into this camp for login window, then there is the option installed, click install and then finish.
10. after all that is done, log off your computer by way of press ctrl + alt + backspace.
11. and now your login window display has changed.
    

good luck.