In the installation and removal of a cylinder of a printing machine, in which the cylinder has a middle drum and two lateral bearing, stubs which are capable of being secured releasably to the drum and of being connected to one another by means of a central spindle which passes through the drum and which at least at one end, can be screwed, by means of a screw connection provided within the outer circumference of the spindle, to the adjacent bearing stub which, with the screw connection released, can be removed, together with its bearing housing, at least to all extent such that the drum is accessible from the side, a high degree of safety and a time saving can be achieved in that, for the change, the drum of a cylinder is released from the bearing stubs and one bearing stub is removed, after which the consequently exposed end of the spindle of the cylinder has connected to it, in the same way as the removable bearing stub, a spindle extension, onto which the drum is pushed and which is then released from the spindle and moved away together with the drum, and vice versa.