There's no easy way, Butty - you will need to remove the gravel, prepare the soil underneath (dig and remove weeds, raking off any stones then levelling the ground)before laying turf or sowing grass seed. It will need watering, and if it's seeded, protection against birds.

Obviously, turf is quicker, but costs more. You lay this offset, like bricks, and brush a little soil in the joints. Whichever you choose will need to be watered, and you can't walk on it until it's settled and growing well.

If you decide on seed, it would pay you to look at the use you will make of your lawn, to get the correct seed.

Also check the sun exposure and degree of slope. Both will have a bearing on what kind of grass you plant, and how you water to get it started.

Its for the Uk Tuqb and I doubt he has much of a slope its graveled?

Well, even in the UK, some grasses will balk at less than 4 hours of sun a day, and even as little as 5º of slope can make a difference in watering in those critical hardening off weeks.