1 - 3 hours
Shattered my front panel 4 years ago and had it replaced at a local shop with a thick generic panel which decided to stop working late last year.
Since the first repair used Norman double adhesive tape, panel was already popping off long before it stopped working which made replacement really easy and didn't have to go through the trouble of getting the screen off.
Together with the detailed guide, I had my iPad back up and running in less than 20 minutes!
Make sure to clean all surfaces before installation, it's pretty annoying to see a couple specks of dust that must have been hiding from the corner after adhering it back to the body.