Follow the step by step guide below and you are there
- Open Mozilla Firefox and install 'Stylish' addon.
- Follow the basic steps to install the addon.
- Restart Firefox after successfully installing the Stylish addon.
- Login to your Facebook Account and click on the small 'S' button in your Firefox status bar.
- Click on "Find Styles for this Site" to open a new tab with free themes to use for Facebook.
- Click on any theme and a preview will be shown.
- If everything is fine in the previewed theme, click on "Install with Stylish" button at the top right corner of the page.
- A dialog box will open.
- Click on Install in the dialog box.
Lets know if this tricks work for you by leaving a comment below, your comment will be fully appreciates