iPad 4th Gen WiFi with a broken front glass.
The instructions were great except that for some reason, they assumed that I would be replacing an intact glass panel. Mine was broken in 4 lines, and every time I got to another break, it would shatter down to powdered glass and glue (Yes I know it is 3M tape).
My time estimate was off by a significant factor.
It will probably take me another hour to finish cleaning the surfaces before I can reassemble.
Don't try to replace the glass unless you have a lot of time and a clean work surface.