Hi,
You have several right ideas - especially on getting the lawn cut!

As for laying the lawn, kill it off with round up, wait 6 weeks for it
to be dead, then dig it over and make fine tilth. You may want to
improve the soil whilst you are at it - depends on what you soil is
like. If you can get hold of large blocks of coir, make it up and work
it in along with some slow release fertiliser. Seaweed meal is also
great as the alginates help bid the soil and help retain water.
Firm the soildown, by walking over it, then re level.
Lay turf and water water water. Dont let it dry out.

Good Luck

Cliff
Bawtry, Doncaster, South Yorkshire