Can you get or do you have access to a tractor with a belly scrape, bucket or box blade? If so just level it out. If not make a drag out of a pallet and pile it up with something heavy like cynder blocks. Secure them to the pallet in some fashion. Tie down straps work pretty well. Pull it over the freshly tilled soil with an atv and it should level out fine. If you have clay soil or clay under the topsoil you may want to put sand on it till, then level. Also you may want to throw some root crops in your seed to further help if there is clay. They will grow and displace it then rot leaving voids to promote better drainage and leave behind some good organic matter. To go cheap you could use purple top turnips or a sugar beet.

Blessings