Dead pixels on widescreen head unit.

[Longnose]

My E46 widescreen head unit display has an increasing number of dead pixels which now obscure the image. The secondhand ones on Ebay all seem the same, so it must be a general problem. Does anybody know a screen replacement service or a DIY ? I don't want to go with one of the aftermarket all-in-one units.

Thanks for any info.