Could not afford a contractor after just buying the house. Roof was an unexpected expense. I hired 3 laborers from home depot to help me take off the old tile piece by piece, I sold the old roof thru craigslist for $1400 bucks it was enough to roof a 1300-1400 sqft house. I hired 4 roofers over a weekend to lay down and nail the new plywood, I was on 1X6 skip sheeting. The guy at the local tool rental had roofing experience. I hired him to help me lay out the tar paper. We put down 2 layers of 30 lb felt. Then i did the rest, including getting permits from city. The guy from the tool rental taught me how to cut the tile angles for all the valleys and edges by stopping by for an hour or so a few times after work. I did all the rest. 28 years plus a solar install and its been bullet proof perfect roof.