Remove Your Old Lawn
If you are removing a healthy lawn, rent a sod cutter, so you can relocate your lawn to someone else who can use it. If your lawn is in poor condition and beyond saving, you'll still need to remove the clumps of grass and level the area.
You'll need a good shovel, wheelbarrow, and gloves for this job. Plus some large organic waste bins to dump your old lawn into. If you've got a sprinkler system installed, you can decide if you want to pull it up or just leave it. It's probably best to just pull the exposed sprinkler heads to help even out the ground, and if you or a new homeowner ever wants to install grass again, you can just re-attach the heads.