Yesterday I installed a new lawn in my backyard. I tore up the old lawn with a sod cutter, an oak tree that had fallen during a storm was removed, the stump was ground up. I put some new topsoil down and leveled the best I could with a rake. The lawn looks pretty good from a far, but while you are walking on it you would notice that it is still bumpy. Is there anything that I can do after the sod has been laid to even out some of the bumps? Here is a picture from upstairs.