Oh, If you watched the videos about caliper alignment you have seen the videos about: loosen the cliper, press the lever, and tighten again.

That's crap in my opinion.

It's way easier and more precise to position the caliper manually. You just get behind the caliper and with slightly loose bolts, move it until you can see light on both sides of the pads, then tighten it. You'll probably notice that when you tighten it it tends to move slightly because of the torque of the bolts, so you have to hold it in place when tightening, or account for the movement beforehand, if you want a precise adjustment. This is one of the reasons why the "press lever and tighten" method is crap.

You'll also notice that most rotors are not perfectly flat, so you'll probably have to reach a compromise when aligning the caliper. You'll have to rotate the wheel several times during the procedure to make sure it works during the whole rotation. This is another reason why the "press lever and tighten" method is crap.

If you discover you can't align it because it always touches somewhere, the rotor is bent and it's time to grab an adjustable spanner and straighten it.