What to do with existing lawn?

[nmudhar]

I'm looking to lay a new lawn from seeds as the current lawn is extremely uneven.
I'm going to use a cultivator to prepare the soil. Do you agree?
What do I do with the existing lawn. Will the cultivator turn the lawn upside down to leave just the soil or do I have to dispose of the existing lawn?

Many thanks,
Mr Mudhar

[Janpot]

You could just take off the top turf, level the soil underneath and then re lay the turf. Adding extra grass seed if needed?