Abstract: A method for resupplying a remote cassette assembly (14) for an ambulatory medical infusion pump (10) with a new replacement tube (22a) includes the steps of disassembling a used tube assembly (22) from the cassette assembly (14) by removing a luer lock (34) located at the end of microbore tubing (32) by severing the tubing (22), removing the tubing (22) by passing it through apertures (30), (25) and (47) in the cassette assembly (14), inserting a new unused tubing (22a) into the access slot (40) to the interior of said cassette, and by inserting tubing (22a) such that the tubing (22a) is pulled through the apertures (47), (25) and (30).