Open your Facebook development dashboard. Click the "Static FBML" link next to the inactive app you want to edit.
The Facebook markup language lets you create customized Facebook applications for your fan pages. You use the Facebook developer section to edit the FBML for inactive programs. You edit the code until you are ready to promote the code to the live page on your Facebook page. Facebook includes an editor in your development dashboard included with the Facebook development setup.
Click the "Edit" link under the FBML name on the next screen. An editor displays with your current inactive FBML code.
Edit the code in the editor. For instance, if you want to edit the h2 tags to a custom text, use the following code to edit the h2 tags:
Click "Save Changes" to save the changes to the inactive code. Because the code is inactive, it does not take effect until you promote the changes to the live site.