Took 2 roots. If at first I assembled one and was a little perplexed how it would work if the lower part was not movable. After assembling the second one, I noticed that, according to the idea, it should rotate. Clamping the first bracket between my legs and applying maximum effort, I was still able to turn it a little. Then it's up to the small, turning it one way or the other, I was still able to make a decent scrolling of this place without much effort.