Okay, I'll take a leap. From what I can see in the photo, there are two holes on the surround in the middle of the distance scale dial. These indicate a tensioning plate for the dial. There is also a screw head on top of the body, in line with the eyepiece and front window. This may be the adjustment point.
Set the distance scale dial at Infinity, and hold it there with your fingers. Using a pin wrench or pliers, turn the tensioning plate either clockwise, or counter. You need to test it out a bit before giving it any big torque, so you don't snap it off, or slip and scar the device like the one in the photo.
Now that the dial is loose, use the screwhead on the top of the body to adjust for Infinity. Look at something that is at least 100ft/97m away, or even further. Once that is done, set the dial at Infinity, and again while holding it with your fingers, tighten the tensioning plate. Check the other distances to see if they match up, but do not adjust for any particular distance, as this will just throw the whole thing out of adjustment again. Just change what you use for your Infinity point if neccessary, and readjust for that. But never closer than 100ft.
Please get a second opinion before attempting this adjustment. I could be completely wrong as to the mechanics of the operation (what each part does). There wasn't much information to go on.