A method of editing an assembly with CAD includes selecting, through navigation, a first element of a first part among parts displayed on a CAD screen, the parts being made of sheet metal and being assembled into the assembly, the navigation automatically selecting an element of a part under a cursor as the cursor is moved on the CAD screen, dragging the first part including the first element with the cursor in one of horizontal and perpendicular directions relative to the first element, selecting, through navigation, a second element of a second part among the parts displayed on the CAD screen, and attaching the first element of the first part to the second element of the second part.