Go to File > Open. Locate the folder then the file name of your previously saved presentation. Double-click on the file. You have now opened your PowerPoint presentation for editing.
Step 2: Open Master
Go to View > Master then click the master you want to change.
Step 3: Select the Footer
Select the footer then drag it to a new position or change text attributes like font, size, style, color, or whether it is subscript or superscript. You can change text attributes before, after, or as you type text.
Step 4: View Changes
When you have completed your changes you can view the results by clicking View > Slide Sorter. The graphic layout will display the newly edited footer text.