I find it best to cock the hammer just enough so that both the hammer itself and the hand are withdrawn into the frame of the gun. Then the cylinder drops out freely and installs freely.
Absolutely, without doing so, you have to give the cylinder a little clockwise turn to "roll it into the hand" so to speak. Cylinder pouches as Willie suggests would make the process so much easier. I personally leave it in the half cock position, I've gotten used to just giving the cylinder a little turn to mesh with the hand. And Willie is right again, about the huge markings on Pietta Firearms. But another Suggestion is Cimmeron Firearms, the markings on those are so tiny they are hard to see even holding the pistol up close. They also have different finishes to pick from, depending on what look you may be going for.