Hedge bed removal

I recently purchased a home back in November which sits on a corner lot. The previous owner had planted run of boxwood hedges that cover the entire front perimeter of the yard. I would guess there are probably close to 40-50 total hedges. Due to some neglect and poor maintenance of the previous owner the look of his design is pretty nasty.
So, I am going to be removing every hedge and filling the entire area with grass seed. I am not a landscaping professional and this is my first home. Common sense tells me to remove the hedges, weeds, roots and rocks first and conserving as much soil from the hedges as possible. Second, preparing the existing soil by hand raking, tilling, etc. Throwing a thin layer of new top soil in, adding seed, cover seed with another layer of top soil, rolling the area or atleast making sure it's level, covering with hay, and then watering 3-4 times a day. I also read that I should use a starter fertilizer as well, but I wasnt sure when to apply.
If there are any experienced landscapers in here that could share some wisdom, I would greatly appreciate it! Thanks a bunch!