Homeowners level the ground on their land for a variety of reasons. Some do this before building a new house, especially when the property has hills. Others, to prepare new above-ground pools, scales, sidewalks, sheds or patios. Some people do this even before planting grass seeds, flowers, and vegetable gardens. Whatever your reason for leveling the ground, the process is the same.
Steps
Part 1 of 3: Branding Your Area

Step 1. Limit the area to be levelled
It doesn't have to be perfectly square or rectangular unless you're planning on using grass instead of simply replanting your grass. Place wooden or plastic stakes around the area to be leveled.

Step 2. Use a mason line level
Tie mason lines and stretch them between the stakes a few inches above the ground. Attach a level of line to them to determine the high point. Typically, this will be your starting point, and the rest of the terrain will be taken to this point, but you can also downgrade a bit if it makes more sense for your project.

Step 3. Adjust the lines
Using a tape measure and your level, adjust them until you can see how much height needs to be added or removed across the area being adjusted.

Step 4. Adjust the incline
Keep in mind that you may want to adjust the slope of your land to help combat drainage issues. It should be tilted 1" for every 4', starting from your square.
Part 2 of 3: Leveling the Ground

Step 1. If necessary, remove the grass
If you're going to work in a small area and your main goal is leveling, you probably won't need to remove the grass. However, if you have a large area and a lot of leveling to do, clearing it out will be much easier. A simple shovel is all that is needed for a fair amount of space.

Step 2. Add your ground cover
Depending on how much soil you have to cover and what you cover next, you will need to level your land with different fertilizer, sand and compost/manure mixes. If you want to grow grass in this area, the cover will have to be nutrient-rich. If you are simply looking to set up a small shed or pool, dirt and sand will work just fine.

Step 3. Spread the topsoil
Use a rake to evenly spread the material, checking through its level and a tape measure to make sure it's staying level. If you have a large area to cover, there are small versions of ground moving equipment that you can rent from your local hardware store. They will be able to advise you on what will work best on your property.

Step 4. Punch the ground
If you're going to level a small area, you can pound the ground using your foot and the bottom of your rake. If it's a large area, or it's especially important to keep level (such as if you're building a structure), get a tamper or slab compactor to compact the soil.

Step 5. Let it settle
Give the soil plenty of time to settle. It needs at least 48 hours, if not several days or weeks, to settle down properly. Water the area with water if it does not receive rain during this period.
Part 3 of 3: Replanting Your Grass

Step 1. Spread your seeds
If you are planning to reintroduce grass in this area, you will need to purchase seeds that are suitable for your needs and those of the area in which you live. Pick up your seeds as well as a hand seed drill or other tool to spread them evenly.

Step 2. Lightly cover with more earth
Lightly cover the seeds with a little topsoil and gently tamp.

Step 3. Water lightly
Water the area with water four times a day for at least 2 days to encourage the seeds to germinate.

Step 4. Reseed as needed
Allow time for the grass to grow and then replant areas where it has not grown to your liking.

Step 5. Alternatively, buy grass
You can also buy turf if you're impatient or want a particularly uniform look.