What I did; I needed about a week of good weather(its wet here in the P.N.W.).
First step is very hard on a mower and blades. Scalp mow best you can without tearing up the mower to badly. Till one direction, Next day till again at 90 to first, next day till again at a 45. All tilling was done at a very slow forward travel rate. (One could drag prior to next day tilling. I did not) The reason I waited a day between tilling is to let the grass root trapped dirt dry up a bit.
Took a piece of chain link fence and attached it to the bottom of a large timber, 4" from the front end of the fencing, with a 2nd piece attached on top about 12" from the back end of the chain link, I tied the front end of the chain link to the tractor (4 points on fence to the hitch). This lifts the chain link and first timber up a little and allows the clumps to get mashed under it. Which leveled and broke up the "root dirt". Rolled it with a tow behind water weighted roller. Aerated it with a tow behind plug aerator, then over seeded.