If you can the release the wedge and one of the bottom bars on the national hive frame then have three lengths of plastic coated garden wire long enough to go around a Langstroth frame and lie the langstroth on the flat with its wedge bar removed on top of the wires and then put the national on top of it and cut the wax on the sidebars. The national brood etc should slip out in position n the Langstroth and remove the national frame. The wire loops in the national foundation/comb will be showing so wiggle the wax up into the Langstroth where the wedge goesand put the wedge in and nail, lining up the nails with the loops. Then bring the three wires round the wax and frame and twist them to hold the brood wax vertical and put into the hive. The bees will fill the whole frame over time and with care you'll be able to get the garden wires out if you need to. Hope this helps.