The convergence of this monitor was not adjusted when I got it. A new deflection board was installed shortly before the monitor was sold, and no real adjustments were made, so I had to do it myself.
The beam landing adjustment is a universal setting. But convergence is set up for every single resolution / display mode. There are several modes I have not adjusted yet so I can easily demonstrate how the process works.

This is what the screen for adjusting convergence looks like. It tells you what mode we are adjusting, 480i, aspect ratio 4:3 in underscan mode. You have this grid and a cursor that's currently in the middle. When you are making adjustments, the changes only affect the small sector marked by the cursor.

Let's zoom in on the bottom right corner of the screen. The lines should be white, but they are not. We need to do something here.

Now I have moved the cursor to the position I want to adjust.

To make adjustments you have to use the 4 knobs on the control unit. Contrast is for horizontal convergence, chroma for vertical convergence, brightness for horizontal green convergence and phase for vertical green convergence.

Working with those white lines is not ideal, you can barely see what you are doing. The control unit allows you to disable each of the 3 beams. What I always do is it to disable the green beam and then adjust horizontal and vertical convergence.

I have now adjusted that one small area. And as you can see everything else is still the same. You really have to turn these knobs to actually see a difference. And the monitor does not show you any numbers of how much you've altered the settings, it's purely visual.

Fast forward a couple minutes. I have now adjusted some more sectors.

Once horizontal and vertical convergence is adjusted, you can go over to adjust horizontal and vertical green convergence. Reenable the green beam and disable the blue beam.
The picture turned out quite blurry, I must have moved the camera too much, but I think you can see that the second line from the top does not look right. Red and green are not aligned.

After green convergence is adjusted you are done. Reenable the blue beam and you should have perfect white lines.

If you are fast you can do the whole screen in about 30 minutes. But 45 minutes is more realistic. Of course it also depends how good or bad the convergence is.

Like I mentioned before, convergence is not a universal setting. So if you would adjust every resolution/mode there is you will be busy for a long time. Let's see how many modes there are:

480i60 4:3 Normal
480i60 4:3 Underscan
480i60 16:9 Normal
480i60 16:9 Underscan
575i50 4:3 Normal
575i50 4:3 Underscan
575i50 16:9 Normal
575i50 16:9 Underscan
480p60 4:3 Normal
480p60 4:3 Underscan
480p60 16:9 Normal
480p60 16:9 Underscan
575p50 4:3 Normal
575p50 4:3 Underscan
575p50 16:9 Normal
575p50 16:9 Underscan
720p60 16:9 Normal
720p60 16:9 Underscan
720p50 16:9 Normal
720p50 16:9 Underscan
1080i60 16:9 Normal
1080i60 16:9 Underscan
1080i50 16:9 Normal
1080i50 16:9 Underscan
1080psf24 16:9 Normal
1080psf24 16:9 Underscan

That's 26 modes. Of course you won't use all of them. Especially 1080psf24, I have no idea how to generate that kind of signal, it's not the same as 1080p24.

And by the way, you cannot change the grid or you use your own grid for adjusting convergence. The screen gets the job done, but I would have preferred a grid with more lines.

Also, the first time I adjusted the convergence something weird happened. After about 30 minutes the screen made this plong sound and went completely black, but came right back. I was very close to finishing the adjustments so I continued. This phenomenon happened a couple more times and more frequently the next few minutes. I completed the adjustments and was happy with the results. But the next day I turned the monitor back on, convergence had reverted to the previous state. This was the only time this monitor has shown such "scary" behavior. I have since redone the adjustments and the changes are still there to this day. After this experience I don't adjust convergence in one go anymore, I only adjust like two rows or columns at once, then safe, wait a bit and then continue.

Anyway, once convergence is correct you could go on to adjust white uniformity. The process is similar to that of convergence and also needs to be done for every mode. You have a white screen where you can adjust the RGB levels sector by sector. I won't cover this here since I have not adjusted it yet, I don't need perfect whites, I'm not using this monitor for professional work.