To everyone saying this is 'over complicated' (or words to that effect)...
Apple have to cover themselves and make the process as robust and fool proof as possible. Yes, you could heat up the display with an electric blanket (which I don't have by the way, so would have to purchase, Apple are not going to send out heated blankets in their repair kits...) but what if it doesn't quite work properly and you crack the screen taking it off - is that then Apple's fault?? Yes you could use a 'properly weighted roller' but again, what if you apply too much pressure whilst doing it and break the screen - Apple's fault??
If Apple had sent out a typical iFixit kit, people would be complaining its too simplistic... If you want to repair it yourself, Apple are not going to advise you do it in the cheapest/simplest way possible, it just leaves them wide open for complaints/suing when things inevitably go wrong with that approach...
Apple can ship a 20 lb display heater, but nope, they couldn't possibly ship an electric blanket for electronics repair.
You can:
- Over-apply pressure using the display press.
- Over torque the screws.
- Over heat the display (it's 400W).
It should be obvious DIY'ers take on risk. The tools that Apple ships doesn't stop any of that.