To change Firefox themes follow the below simple steps..,
1.Turn on your computer and start the internet and Mozilla Firefox. Navigate to TOOLS/ADD-ONS menu. This will display the add-ons screen. You will see the EXTENSIONS view. Click on the THEMES tab to see available themes. You will only see the default theme installed. Click on the GET THEMES link at the bottom of the menu.
2.A new tab will open displaying the themes page. Scroll through the list to find the extension you want to add .
3.Select the theme you want.
Once you have selected a theme, click on the title text to download the theme you chose.
4.Clicking on the title will take you to that theme's download page. You can read about the theme and then download it by clicking on the INSTALL NOW button.
5.After clicking the INSTALL NOW button, a new small window will open providing some warnings and giving you one last chance to exit or install. Click INSTALL.
6.After installation, a new window will open announcing success and allowing you to click to restart Firefox. After restarting, Firefox will take you back to the themes menu where you will see your new theme displayed on the list.
7.Select the new theme and click enable. Restart Firefox and your browser will be customized with your new theme select.
Enjoy Using New Themes