You may be able to do this and keep the old internals of the hub. You need a thread pitch guage and a set of calipers that read in mm's. You can get both at a discount tool store pretty cheap. Anyway, get the thread pitch off your existing axle, get the dia. of the axle in mm's, and the length in mm's. Then go to www.loosescrews.com and see it they have a replacement axle for you that is hollow. (You may have to buy a complete new axle with cones if they don't so have as much info about the hub handy as possible.) Rebuild the hub with the new axle, making sure the spacers are all reinstalled correctly. Obviously you'll need to get a skewer too. Check Barnett's for the proper procedure for rebuilding and adjusting the hub cones.