Use the opening tool again on the left and right sides.

Start prying at the areas closer to the rear of the laptop (near the display hinges) before moving towards areas that are closer to the front of the laptop (away from the display hinges).

Pry a little bit on the left side, then pry a little bit on the right side before prying more on the left side again. Working on both sides in this incremental fashion is easier than completely prying one side before starting the other side.