A guide assembly (6, 6a, 6b) for a moveably arranged closure member of an open-roof system of a vehicle, the open-roof system having a closed position, in which the closure member covers an opening in a roof of the vehicle, and an open position, in which the opening is at least partly uncovered, the guide assembly comprising a. a guide extending in a longitudinal direction of the vehicle; b. a mounting element for mounting the closure member; c. a first support mechanism operatively coupled to the mounting element, wherein the first support mechanism slidably supports the mounting element in the guide; d. a second support mechanism coupled to the guide and comprising a support element supporting the mounting element slidably along the mounting element, the second support mechanism being configured for moving the mounting element in a tilt direction to a tilted position, the tilt direction being substantially perpendicular to the longitudinal direction; wherein the guide assembly is provided with releasing means for releasing the mounting element from at least one of the first support mechanism and the second support mechanism and for remounting the mounting element; characterized by the guide assembly further comprising e. a locking mechanism arranged in the guide and operatively coupled to the second support mechanism for operating the second support mechanism and locking the second support mechanism in the tilted position, wherein the guide assembly is configured to operate the locking mechanism when moving the first support mechanism between the closed position and an intermediate position, in which intermediate position the opening is partly covered by the closure member; and wherein the releasing means are configured for rendering the locking mechanism temporarily inoperable for enabling to move the first support mechanism towards the closed position without operating the second support mechanism and to thereby slideably release the mounting element from the second support mechanism. a. a guide extending in a longitudinal direction of the vehicle; b. a mounting element for mounting the closure member; c. a first support mechanism operatively coupled to the mounting element, wherein the first support mechanism slidably supports the mounting element in the guide; d. a second support mechanism coupled to the guide and comprising a support element supporting the mounting element slidably along the mounting element, the second support mechanism being configured for moving the mounting element in a tilt direction to a tilted position, the tilt direction being substantially perpendicular to the longitudinal direction; e. a locking mechanism arranged in the guide and operatively coupled to the second support mechanism for operating the second support mechanism and locking the second support mechanism in the tilted position, wherein the guide assembly is configured to operate the locking mechanism when moving the first support mechanism between the closed position and an intermediate position, in which intermediate position the opening is partly covered by the closure member; and wherein the releasing means are configured for rendering the locking mechanism temporarily inoperable for enabling to move the first support mechanism towards the closed position without operating the second support mechanism and to thereby slideably release the mounting element from the second support mechanism.