Measure the area you plan to use for a tennis court. Try to leave an extra 10 to 15 feet around the court.
Remove the old grass with the sod machine. This machine can be rented at a rental store and will cut under the old grass and you can then just roll it up after you are done and dispose of it. If you have neighbors and friends who need a lawn repair, you can also give it to them.
Spread the topsoil out with the shovel, then level it with the back of the garden rake. Toss fertilizer on top of the dirt and mix in with the rake. Level the soil again.
Spread the grass seed out. You will want to make the seed thick. This is a situation where you will want to over-seed. This will make the surface thicker.
Water the grass a couple of times a day. Do not cut it or walk on it for at least a month. This will assure that the roots are established. The first cut needs to be a normal grass cutting. Do not try to cut it too close. Gradually you can lower the mower by a half-inch per cutting. A good home grass tennis court will have grass an inch and a half high.