1 - 2 hours
The iPad mini microphone stopped working one day...I suspect it was due to my daughter dropping the device, but not certain. The glass screen shattered due to my daughter dropping it...or at least that is the story. Rather than buy a new device, decided to take on the challenge (and it was).
In the end the repair was successful....but pretty difficult. The hardest part was dealing with the shards of broken glass and the slow process of removing the pieces....you have to go slow or else you might damage the lcd screen. The broken screen added another 3+ hours of time on to the process and is very messy. Since the screen was cracked, the suction cup was not helpful. The instructions were very easy to follow and laid out the steps very clearly. I had to start on the left side of the device because that is where the suction cup worked best. The only thing that could have been more clear was ensuring the new digitizer contacts have tape on them when you put the replacement screen on. I luckily read ahead in the comments and saw that was an issue so was somewhat prepared. The new digitizer that ifixit sent did have a piece of tape on it, but I initially removed it thinking it was just for protection....I quickly re-applied it once I understood the purpose...again this is important and needs to be more clear.
First off, set aside a few hours of uninterrupted time so you can concentrate. Make sure you have really good light so you can clearly see parts and pieces of glass (which can become almost microscopic). I wish I had a magnifying glass or glasses....when you get the digitizer screen and lcd off, you start dealing with some very small parts and connectors/sockets that need to be reattached without damaging them....my eyesight is decent and I think I got lucky attaching these but magnifying glasses would have helped. Wear eye protection! This is critical! You do not want a piece of glass in your eye. Have a vacuum next to you and suck up the broken glass as you go along. Do this in an area away from pets, kids, food, drink....again the glass will pop up and out in tiny shards and you never know where it is going to go. Get the toolkit that ifixit sells (mine was bundled with digitizer)...it has everything you need. As you are in the process taking off the old screen, take a look at the back of the new screen to get a sense of where parts are at that could be damaged with the guitar pick (this just adds to the nice instructions). Lastly, don't rush it! Take your time and enjoy the process.