03-30-2012 05:05 PM
I don't know about the iOS version, but in Android you do a long press on a highlighted section and a menu will pop up with the option to delete the highlighting. I have had trouble with places where I had accidentally highlighted a single, short word (like "an" or "to"); it's pretty difficult to accurately press on such a small word.
01-07-2013 09:18 AM
01-23-2014 10:06 PM
Please tap the icon at the top of the book's page next to the Library button (its icon looks like three bullet-pointed lines) and then tap Notes on the screen that you are taken to, you should see a list of the notes and highlights that you've made in that book - swipe across the one that you want to remove and a Delete should appear on the right-hand end of it. Tap the Resume button at top left of the page to go back to where you were in the book.
Another quick way of unhighlighting is to just simply tap the highlight word, then tap the symbol that is a circle with a red line through it next to the highliting colour option. This will unhighlight anything that you highlited along with that word.