And so it’s natural we start here. Use highlight mode: Click the Highlight button (so it turns gray), click the down arrow If you want to password-protect or remove the password on a PDF, you will need the professional version of Acrobat, which requires a In the Preview app on your Mac, open the PDF you want to changeDo any of the following: Quickly highlight, underline, or strike through text: Select text, click the down arrow next to the Highlight button, then choose a highlight color, underl