My brother *stepped* on his iPad 4 and hella cracked the outer glass screen.
Opening the iPad at first was slightly difficult, something that can be perfected with experience. The rest went very smoothly. iFixit iPad screens were too expensive so I bought off Amazon for 25$, but the tool kit I bought from Ifixit was something you just cant find anywhere else. nice selection of tools. the iPad openers, the blue sharp ended pens were very crappy makes, they bent the first time I tried to pry up the iPad screen, but everything else was great. i included a picture of the old bezel and digitizer that was replaced. if you're replacing a broken outer glass screen, be prepared for the glass to crack more as you attempt to open up the iPad. wear glasses, even if you feel stupid, because glass shards WILL fly and chip off...
be very careful when first opening the ipad and cutting the adhesive. especially the bottom left corner. ifixit warns you, but once you get started you want to just do it yourself from there. be smart and follow the directions, or you can sever ribbon cables underneath the edges of the screen. everything else is easy, just be careful and use canned air to clean off dust and small glass shards. if small glass gets everywhere, use a slice of bread to pick then up. it sounds crazy, but bread makes the pieces stick to it very well.