closed releasing of all fixation devices which are associated to the rollers disposed below the roller to be replaced lowering the roller to be replaced and all rollers which are disposed therebelow in this case the respective supporting devices move until the lower abutment the corresponding sliding members are lowered and simultaneously the shape of the fixation devices is modified after a predetermined lowering displacement of the roller stack the fixation device associated with the roller to be replaced is blocked the rollers disposed below the roller to be replaced are further lowered once the replacement of the roller has been effected all fixing devices associated to the rollers disposed below the replaced roller are set in such a manner that a raising movement of the sliding members is possible the calender is slowly closed by raising the lower roller in this case the support devices come into engagement against the upper abutment when the displaced rollers reach the vicinity of the desired position the respective fixing devices are blocked the rollers are brought in the desired position by further lowering of the lower roller without modifying the position of the sliding members in the event that the uppermost roller of the calender is not or only slightly movable in the pressing direction a pressure supply of the fixation devices 6 associated with the rollers disposed therebelow can ensure as long as the roller stack is still closed after the raising displacement that the support device 8 is brought to a position for this purpose between the end abutments the same purpose can also be achieved by the pressurization of the correspondingly designed support devices 8 themselves it can also be advantageous to adjust or to maintain the support devices 8 by.