How do you apply sod to a lawn?
The way that I have always doen it and it worked just fine was first to wet the ground real good. Then just lay the sod over it. Either roll it out if you have enough to cover hte whole area. Or you can space the sod squares every so many feet and the grass will fill in over time. You can also combine this with throwing down seed and cover it with straw to fill any spots that dont have sod. You have to keep the sod moist until it takes root real good. I usually water it in the morning so that the sun doesnt dry it out. I you. Good luck. It's very important to rake the soil before you lay the sod. This will loosen the top 1"-2" of soil and make it easier for the grass to root. Make sure you water it well. New sod needs 1" of water per day for the first 3 weeks after it's laid. Once it's established it only needs 1" per week for optimal growth.
It pays to destroy the old one first, perhaps with roundup, and level any hollows by filling with sand