I agree with the previous two comments—this guide (or a separate one) should be changed to show to replace a cracked/shattered digitizer. I quickly learned that using the picks was a lost cause and following the guide was near pointless until I got to removing the display.

Pro-tip: don't even bother with the heat gun if the digitizer is shattered. Take the iPad outside, put on a pair of goggles, and just wedge a spudger/tweezers between the adhesive and the glass. Don't worry about damaging the home button or cables, your replacement digitizer probably has them pre-installed...just worry about the camera and not nicking the display. It's going to make a huge mess, but that's why you're outside. Heat it if you want, but I didn't find it necessary.