Do note that after banning or removing someone from your Facebook Page, the user will no longer be able to post, comments and interact with your Page. However, the user will still be able to see your Facebook Page updates since your page is set to available for Public.
Here’s how you can remove someone from Facebook Fan Page.
Login to your Facebook and select your Facebook Page in the top-right under Your Pages. Once your Facebook Page is loaded, click on the Settings link at the top.
Under General Settings, Click on People and Other Pages on the left navigation panel. Here's where you can see the list of people and other pages that like your Facebook Page. To remove or ban someone from your Facebook Page, check the checkbox next to the person name. Click on the gear icon and select Remove from Page Likes or Ban from Page. Facebook will then ask you to confirm your action. Hit on confirm button to proceed.