Make Changes To Read Only Presentation. Once you get to the Info page click Protect Presentation. Click Finder and find your PowerPoint file right click it and choose Get Info.
Then Click Sharing Permissions options and click. You can unlock a read-only PowerPoint presentation by removing the Mark as Final from the file. Click Protect Presentation and select Mark as Final This acts as a toggle selection.
Click Ok to continue.
Click the drop-down arrow icon on the Protect Presentation box and then select Mark as Final option. Prevent users from making changes to Presentation. But Im afraid that it is not available to add comment on a read-only file. Click Finder and find your PowerPoint file right click it and choose Get Info.