15 - 45 minutes
The iPad I worked on I had already fixed the digitizer on once. The second time was the same issue. Broken digitizer. But this time it was bad to the point that I didn't need to go about heating up the glue. It had large holes in it and looked like it was stepped on.
At first... Badly. It took a lot longer to peel all the broken shards out of all the nooks and crannys. Then had to try and clean out the glue and get the smudges off of the LCD. All that work and then I started realizing by the way the LCD was seating in the iPad that the aluminum frame had been bent or warped. I ground down some of the sharp edges so the bezel would lay flat and the screen would be able to fit in. It all fit... Kinda but then when I went to turn it on and test it out the screen just flickered and went out again.
I ended up buying a new bezel (broke the one that was in it at some point. and buying adhesive for it. The bezel I bought from a local store because I wanted to get it done quickly and had to go there for a company device I was having repaired. It came with adhesive already on it and I think that really helped the reinstall.
Back to the nonworking screen. I ended up pulling everything apart and re-seating everything down to the battery. It took a bit longer but it felt like it just wasn't making a connection somewhere. I used some qtips and nail polish remover (diluted acetone) to clean the connections. I usually use this to clean off processors when prepping them for new heat sinks and that seamed to do well. I put all the innards back in and tried to give the frame a slight bend back into a good shape. It didn't really work so I proceeded anyway. I put the bezel in and with the adhesive it worked extremely well. It wasn't trying to jump out of the groove or cling to the LCD cable or anything. I put the LCD back in and used a sterile alcohol wipe to clean off the dust and gunk that had accumulated on it from it being exposed through the shattered digitizer, then dried it and rubbed out any streaks with a glass cleaning cloth.
Reinstalled the digitizer and added more adhesive in the areas that the warp of the frame would be a problem. It stuck pretty well but I had to keep it under a stack of textbooks to really get a good bond.
It may not seem like much and may seem a little scary but grinding down the sharp edges on the frame from being dropped on concrete or other hard surfaces really helps with utilizing the little bit of space it adds for the digitizer, as well as lowering the possibility of cutting yourself or breaking a shiny new digitizer.
Secondly, removing everything may seem excessive and like a waste of time but if it has excessive amounts of broken glass it's a good idea to do it the first time and make sure you get everything seated and reseated without any shards or dust lodged in the terminals.