A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Hello Kaelan,
If you wish to remove a user's permission in a shared file you can perform it through OneDrive. You can refer to this link for instructions: (click here).
Should you have further questions, feel free to reply on this thread.
If you think this was useful, feel free to "mark it as an answer" to help those who are facing the same problem.