The Find and Replace tool on the Page tab lets you enter the text you are looking for to find and/or replace it throughout your diagram.
Find a Word or Phrase
To find a word type it into the Find field and click on the "Find" button. Your word will be highlighted one at a time in the diagram below. Keep clicking the Find button to see all instances of the word or phase.
Replace a Word
To replace a word or phrase, type in the text you want to replace in the Find field and type what you want to replace it with in the Replace field. Next, click either "Replace" to replace each instance one at a time or "Replace All" to replace all instances at once.
You can further refine options by clicking on the gears at the end of the overlay and specify if you want to make sure the search matches cases and that it finds only exact whole word matches.
To exit out of "Find and Replace" hit the "X" in the far right side of the overlay.