usually a 4mm open wrench fits the valve cores. As far as sealant required, a lot of that depends on initial prep such as tapework and fitment of tire to rim. My Marge lites and Nates took some doing, involving lots of sealant, lots of tape, some sill plate insulation, ect. The setup on my Jackalopes with Hodags involved 4oz of sealant, one wrap of packing tape, valve stem, and a hand pump.