You are unable to select the footer elements directly on the slide, you will have to go to the “Slide Master” view and change the footer in the “Master Slide.”
Go to the “View” tab from the ribbon the select the “Slide Master View” option, which is located inside the “Master Views” section. This will take you to the “Slide Master” view.
The slide that is a little bit to the left from all the other slides is the “Master Slide”. Select the footer which will enable you to edit the text inside the “Text Box” of the footer.
After you select the “Text Box” of the footer, edit the text of the footer then select anywhere outside the “Text Box”. Click on the “Close Master Views” option to close the “Slide Master” view.
Step-1 Open the Slide Master view, go to the “Master Slide” and select the “Text Box” of the footer. You have to “Left click” once on the “Text Box”.
While keeping the “Text Box” of the footer in the “Master Slide” selected, hit the “Back Space” on the keyboard of your computer and the footer will be removed instantly.