My friend, a master Gardener, suggested:
1.) scrape off as much of the grass/weeds as you can. Don't sweat the rocks.
2.) cover the area with 10 (yes, 10) layers of newspaper paper. You can go to the newspaper office and ask for the end rolls of blank newspaper. I paid $1.00 for about 200 feet.
3. wet down the newspapers.
4.) mix 1/3 compost, 1/3 garden dirt and 1/3 sand.
Pour on the wet newspapers.
5.) plant seeds.
6.) eat food.