The easiest way to do this is to hit Ctrl+A to select everything in the document and then hold the Ctrl key while clicking each checkbox, in turn, to remove them from the selection. Next, you need to select all of the content in your document except for the text boxes you want to lock. Here, check the box next to “Allow only this type of editing in the document” in the “Editing restrictions” section, then keep “No changes (Read only)” selected in the drop-down menu in the same section. A Restrict Editing pane appears on the right where you can restrict editing permissions for all, or certain parts, of the document.
