Embodiments of the present invention relate to an apparatus and method for high speed automated installation or attachment of preformed handles onto portable containers such as buckets, boxes, cartons, or pails that are moving on a conveyor system through the apparatus. A frame structure supports the apparatus. A container conveyor conveys the portable containers into and out of the apparatus. A handle sheet conveyor conveys sheets of preformed handles from storage containers into a handle magazine. Individual handles are detached from the preformed handle sheets, after which the handles are attached onto the portable containers at a high rate of speed. A slidable handle separation and insertion mechanism includes a main slide for preforming the handles prior to insertion onto the portable containers. In some embodiments the main slide is angled at approximately a 45 degree angle from the horizontal.