Sometimes you may want to ban a particular user from your facebook page because he/she is very annoying or something. Here is the step by step procedure to ban a particular user from your facebook page.
1. First go to the facebook page. On the top right hand side of the page, you will see a 'Page Likes' column (refer pic below)
2. Now hover the mouse over it and you will see a 'See All' option, click on it
3. A list of all liked persons will appear and find the one you want to ban. Click on the settings icon and click 'Remove'. Then you will be asked whether you want to ban the person permanently. Tick the box and you are done.