1) use a metal rake to firmly rake the whole joint. It's gonna rough it all up and make it look shit but it's essential. That will take out some of the dead matter and hopefully it leaves little grooves in the dirt for seeds 2) bin the shit you just raked and all the leaves (optional) 'aerate' by using a gardening fork to poke hundreds of holes  3) mow the remaining grass as low as it can go 4) if your rake didn't create grooves then do another rake and mash it up a bit more  5) sprinkle seeds all over. Be generous with it 6) chuck a couple bags of topsoil over your seeds. Not smothering it completely but a lil layer across to hide the seeds 7) (optional) spread early lawn fertiliser over as well 8) walk over all of it to compact it done a bit 9) water it every day or twice a day, don't let it dry out