Abstract: An impactor apparatus and method for assembling modular orthopedic prosthesis parts includes a base member that can be for example an instrument from a tray or an instrument tray lid. The base member defines a plane and provides a plurality of components extending away from the plane. The tray components include a pair of spaced apart supports. An impactor tool can be removably supported upon the supports in a fixed position relative to the base member, preferably generally parallel thereto. The components include an impact driver tool actuator that pivotally attaches to the base member. A pair of prosthesis parts or components are connectable at a taper lock connection defined by respective tapered annular portions of the prosthesis parts. The components and impact driver tool support the prosthesis parts adjacent the base and axial alignment with the impact driver tool, the prosthesis parts being generally positioned in between the pair of spaced apart supports.