Stocker Steve
Do you intend to reuse the wood? If not I suggest the following. I assume you have a small air compressor or have access to one. Get one of the cheap small air chisels equipped with a punch. Grind the punch to the diameter of the nail head. Simply place the punch on the nail head and give the trigger a brief pull and it will drive the nail through the roofing metal. You can do this far faster than you may imagine. With the heads driven below the sheeting surface you can then simply lift the sheets off. Use an oversize screw with gasket, yes those are made, to reuse the roofing. If you lay the lathing strips out on the same pattern as original then you can reused the existing holes. Once painted the siding will appear as new. I dismantled a commercial chicken house by myself and salvaged all the roof sheeting. I also reused the 2 x wood but I used a flooring saw blade that could handle some nails.