I regularly repair tiles of Unilumen 2.6mm Upad that have broken pixels. Since the pixel pitch (distance between the center of the pixels) is only 2.6mm, that leaves only about 0.5mm between the pixels. Not enough for soldering with conventional means. To do this, you do require good eyes or magnification as well as an hot air station.
It took me quite a while to become proficient at replacing the pixels and performing repairs on pads that had been ripped off.
To repair damaged pads, one can use special (very thin) paper-like circuit board that you can order from Unilumen.
In the process of learning how to deal with these repairs, I created some documentation to make this somewhat easier. I wish I would have had these drawings when I started out as this would have allowed me to get better results sooner. As such, I think it is only fair to share these drawings hoping to help someone else. Below are some of my notes documenting orientation as well as traces on the board itself as well as on the paper. Pictures of the paper are taken through a stereoscopic microscope.
Hope this helps someone!
Dieter Vansteenwegen (ON4DD) 