Digitization and the growing capabilities of data networks enable companies to perform tasks via remote support, which previously required service personnel to travel. But which mixed reality method leads to better results regarding human factors, grounding and performance criteria? This paper reports on a collaborative user study, in which a local worker is guided by a remote expert with the help of different augmented reality methods. The performed task is an controller exchange in a switch cabinet of an industrial robot, a task rather typical for failure detection within the field. Our study was conducted in collaboration with a technician school of which 50 technician apprentices participated in our study. Our results show clear advantages of using augmented reality (AR) to enable remote support. It further gives significant indications for using a projection based AR method.