Before you proceed with this — especially if your digitizer is shattered — read through the comments under each step for some helpful hints. Also, one thing that isn't mentioned: DO NOT ATTEMPT TO CLEAN THE INSIDE OF THE DIGITIZER AFTER YOU REMOVE THE PROTECTIVE FILM. From what I can tell, only the outside of the digitizer is made of gorilla glass, and the inside will lightly scratch no matter how soft and clean your cleaning cloth is.
Why there’s such an obsession with not damaging the cables is beyond me. Be careful, so as not to damage what the cables are connected to. But the cables are part of the replacement digitizer, so if you nick or even slice through them (like I did with the one closest to the bottom) don’t worry about it.
The suction cup is useless if your glass is shattered. Use a new, sharp razor blade, and insert it vertically between the edge of the glass and the metal back of the iPad. Don’t worry about pressing too hard — there’s a lip that stops the blade from going in too far and damaging anything. You’ll probably have to do this several times, but eventually the blade will “bite” into the edge of the glass well enough for you to pry it up. Insert a pick underneath the razor, then remove the razor and continue as directed.
“At least a minute.” Bullshit. Get the iOpener good and hot, place it on the area you’re going to work on clear side down, and cover it with a towel. Walk away for 2 minutes. Make yourself a drink — you’ll need steady hands later.