Super easy - all you need is a soldering iron.

I've had dodgy screens before that I've fixed this way, but I didn't seem to have any contrast wheel related issues you seem to have, so there may be more going on with yours...

I recently bought a modified DMG Gameboy off of ebay, and was disappointed to find that the display had a few vertical lines present on the rightmost side of the screen. I could live with that, but once the game actually started up, the display turned completely white with a few horizontal and vertical lines showing. Upon messing with the contrast slider, the display began to flicker and several more horizontal and vertical columns appeared.

The game was absolutely unplayable like this, so I thought I would ask you guys for some help. Are there any services that do Gameboy screen repairs? Are there any ways that I could fix this myself? Any help is greatly appreciated.