I use a large 1/2 inch drive socket installed backwards on an extension bar to drive out the old races. Use the old races to drive the new races in. Then knock the old races back out. The grease seal can be tapped in with a hammer if you are careful to keep it straight. If you have not done the job before, I would plan on two hours per wheel. With experience, one hour is plenty, assuming no complications. You can buy the bearings, seals and grease at most any parts store.