Basically, and even though most website users feel they are not very important, website footers provide users with the information they are looking for. This is why contact details and a brief information about site or / and site owners need to be placed at the footer. Corporate designs may need to provide driving directions, telephone number, a web form or at least an e-mail.
If your website has a configurable footer, it's most likely controllable via the Widgets. <-- Click on this link to know more about Site and Global Widgets.
Click on the appropriate footer you wish to edit, make the necessary changes, and click on 'Save & Publish' when done.