A downhole retrieval tool includes a mandrel; an inner sleeve disposed around the mandrel; a plurality of magnets coupled to the inner sleeve; and an outer sleeve disposed around the plurality of magnets, wherein the inner sleeve and the plurality of magnets are rotatable relative to the mandrel. In another aspect, an assembly tool for handling a magnet includes an anchor; a conveyance movable relative to the anchor; and a magnet holder coupled to the conveyance, wherein the magnet holder includes an arm for retaining the magnet.