The beamline optics of the vacuum-ultraviolet radiation beamline installed on a bending magnet of the Swiss Light Source are to be upgraded. Supports for all three optical elements of the beamline optics (collimating mirror, plane grating monochromator and focusing mirror) have been re-designed to allow a more stable and improved fine tuning. The monochromator is composed of a set of three interchangeable gratings mounted on a rotatable platform. Each grating is framed in an optimized goniometer mount, designed and built in-house, which uses flexible elements for precise and reproducible adjustments. The roll and yaw of the gratings can be adjusted with microradian precision to minimize conical diffraction.