Isn't one of the steps to drill a hole or two in the cluster to access a couple of hidden screws? I'm sure I saw that in one of the DIY videos...
I have three columns out on my MID but it's not getting any worse and it doesn't affect most text displays -but I will drop in the pixelfix silver cable sometime soon though.
*edit* here's a walk through from a 7 series forum - pretty sure the cluster is very similar: -
PIXEL FIX DIY write up, about a 2 hour job and some patience (Long pic warning)
I also found this note note on here (from TrickerZ)...
"Drilling the holes is the easiest option so you don't have to mess with the needles. If you really want to do it without drilling holes, you need to take
pliers and grab the shaft of each needle from behind right between the motor and the PCB and then pull the cap off (try not to twist too much or you'll screw up the spring). To make it easier to replace the needles, move the needle (usually has to be pulled past the little pin) counter clockwise until you feel it stop. Once you know where the needle should be at the stop, you can line it up at that stop when reinstalling it. Otherwise you have to run the car and calibrate it. RPM, fuel and coolant are easy, the MPG and speedo are difficult. RPM should read about 500 at idle when the car is warm, coolant should be in the middle when car is warm and fuel should be at full when the tank is full. You would need GPS or someone driving beside you to calibrate speed and MPG is pretty much impossible I think. I guess you could floor it before taking it out and see where it peaks and make note of that, then try it after installing the needle and see if it ends up in the same spot. "