Abstract: A method is disclosed in which the excavator base is assembled, the swing gear is fastened in place on the base and the swing bearing is assembled on a lower bearing pad which extends in a circle around the swing gear. The revolving frame is assembled over the base and raised on jacks and leveled. Temporary rollers are placed on a reference surface formed on the top of the swing gear and the revolving frame is lowered onto them. A section of the swing bearing assembly is removed and a metal cutting machine having an upward directed cutting tool is mounted in its place. The revolving frame is swung on the temporary rollers and the cutting tool machines the upper bearing pad disposed on the bottom side of the revolving frame. The metal cutting machine and temporary rollers are then removed, the swing bearing section is replaced and the revolving frame is lowered back into place where it rests on the swing bearing assembly.