I've added this page giving basic rangefinder adjustment instructions for those who want it.
The horizontal adjustment can be made by removing the slotted head screw on the back of the camera and using a flat bladed screwdriver through the hole to make the adjustment.
The alignment of the hole to the screw isn't perfect and there are a couple of things hindering access too. A very thin screwdriver can get access to the screw but making fine adjustments isn't easy. Look at the Rangefinder Modifications page to see the problem.
To adjust the vertical alignment, the rangefinder cover has to be removed. Look at the Dismantling page to see how to do that. Once off, the vertical adjustment can be made using the screw shown in the picture below.
However, when the rangefinder cover is refitted, the vertical alignment will almost certainly change. This is one of the biggest problems with the camera. The problem can be improved by fitting some washers under the pillars that the rangefinder cover screws fit in to. See the Rangefinder Modifications page to see how to do this.