An interface and a method for mounting a piece of equipment (5) with a rotary drive source (3). The mounting interface has a first frame (1) fastened to the drive source (3) and a second frame (2) fastened to the piece of equipment (5), the frames (1, 2) being fitted with assembly means (19) for assembling them together. Rails (22, 23) for guiding the piece of equipment (5) are removably mounted on the first frame (1) and co-operate with windows (20, 21) of the second frame (2). The windows (20, 21) are laterally open providing transverse passages for the rails (22, 23) into the windows (20, 21). The piece of equipment (5) can be moved transversely by an operator towards the rails (22, 23) in order to support it and guide it axially towards the drive source (5).