Abstract: A method of changing the mold assembly upon a plastic molding machine having fixed and movable platens mounting a mold assembly to be replaced which comprises the steps: positioning the replacement mold assembly upon a floor surface spaced from and in the plane of the fixed platen, aligning an overhead crane with a cable and support track within the plane for reciprocal movements of the crane and positioning the crane to overlie the machine and hooking the cable to the mold assembly. Further steps include disconnecting the fasteners between the mounting plates on the mold assembly and platens and with the platens separated, lifting the mold assembly from the platens and transporting the mold assembly in the platen plane and lowering the mold assembly to the floor surface in alignment with a replacement mold assembly.