A kit enables an efficient and contamination-free method of changing a resin used in a three dimensional printer from a first resin to a second resin. The three dimensional printer includes a print engine and a receptacle. The kit includes a conduit assembly and a resin container. The conduit assembly includes a fluid inlet configured to be affixed in the receptacle in an upward orientation, a pump head configured to be coupled to a motorized pump actuator in the receptacle, a first conduit coupling the fluid inlet to the pump head, a fluid outlet configured to supply resin to the print engine, and a second conduit coupling the pump head to the fluid outlet.