The invention relates to a device and a method for the assembly of a sliding sunroof frame and for the adjustment of a cover connected with it in a vehicle. The device has a tool that has one portion that can be introduced into the body of a vehicle and another portion that can be positioned above a roof opening of the vehicle. A positioning assembly for the sliding sunroof frame and the cover and various adjusting component with centering devices are provided on a floating frame on part of the tool positioned in the vehicle body, and allow fully automated raising and alignment, as well as fastening of the sliding sunroof frame to the vehicle roof and complete adjustment without play and fastening of the sliding sunroof cover to its tilting mechanism.