Right-click on a blank part of the page where you want to block an ad, and select "Block Content" from the menu. All the ads and other page elements that you can block will remain in normal full color, while the non-advertising text will turn gray.
Left-click on any ad that you want to block. A red bar that says "Blocked Image" will appear across the ad. You can block one, several or all of the ads on a page. If you block an ad and then change your mind, click on the ad again, and that will unblock it.
Hold down the shift key while you click if you want to block only a specific ad, and not all the ads that are coming from the same source.
Click the "Done" button in the upper left corner when you have finished selecting ads.