leveling my lawn

I taken out a path and laid a wooden edging, increasing my bedding space. I can now see how un-level my lawn is. Having looked at the RHS guide on aereating and leveling, it tells me to lift the turf and dig over the earth. Would using the top dressing be the best for leveling out?
I suppose this is pretty basic stuff but I've never been one for lawns - "as long as it's green."

 

How undulating is its deep holows then strip the turf off the affected areas, put top soil under, grade it and ree lay the turf.