In PowerPoint 2013, whenever you create and save a presentation, your name is automatically put in the "Author" field that appears in the file's metadata. You can change the author's name, or add additional names, when you save the presentation as a new file. Of course, the author's name isn't the only way your name is used when saving a file. If you want to remove all traces of your name, you'll have to go into the document's File Properties window, too.
Open the presentation you want to change in PowerPoint. Click the "File" menu and select "Save As." Give the file a new name if you don't want to write over the original. Note that the last author's name is listed below the Save as Type menu.
Double-click the author's name, press the "Delete" key and type any name you wish in its place. If you want to add more than one author, add a semi-colon after each name. Click the "Save" button.
Launch File Explorer and locate the PowerPoint file. Right-click the file, select "Properties" and then click the "Details" tab. Verify that the name you entered when saving the file appears in the "Authors" line. Regardless of what name you used for the author, your own name appears in the "Last Saved By" line. If you want to remove your name, click the "Remove Properties and Personal Information" link at the bottom of the window.
Click the "Remove the Following Properties From This File" option and then click the Last Saved By check box. You can also remove the version number, or any other field that appears in the window by clicking those check boxes. Make sure the "Authors" check box is clear so you don't delete it by mistake. Click "OK."
Click "OK" to close the Properties window. Before closing the window, you'll see that your name is removed as the person who last saved the file; however, the author's name is still visible.
Review the entire presentation, including its notes, to verify the author's name hasn't been added to any slides.