Depends how big the lump is - I'd cut the turf and lift it to one side, dig out and remove the excess soil and level, and replace the turf.

Cut around the turf a bit bigger than the 'lump' Dig it out if it is a small area and flatten the area. Pulling back the turf. If you use a rotivator it will mess up more lawn than you need. That's what I would do

Hi Woodlarks and welcome to GoY!
The easiest way that I know of for levelling a lawn is to cut the turf off (in squares) where you need it levelled and remove the "hump" then replace the turfs. Give it a good watering and possible a feed and it should recover in a few weeks!
It's hard work but sounds far quicker to recover than using a rotavator on your lawn!

It looks like you've had the same answer from three different gardeners all at the same time! Something in there must be right! Lol

Thank you for all your quick answers - the hump is about 1 foot above the rest of the lawn and is very hard - apart from digging out the soil is there any piece of equipment I can use to dig out the excess soil?

I don't think so Woodlarks. If, like me, you find digging hard or difficult then I usually get our local odd-job-man on the case and he does it for me!

All I can think off is a long handled trowel dont know if this would help, worth a try I guess

Or you could just leave it where it is and call it Quasimodo......:o)

The alternative would be to remove the turf and create a flower bed on the hump.

I need to flatten it out so the football stays in the grass and out of the flower beds!

Ah good luck...

The only piece of equipment I can think of is a mini-digger and that would cause more damage than it is worth. A rotavator will only break up the soil and not move it or level it in any way. Unfortunately there is no 'easy' way of doing it.