I would use a grass rake to think out any dead growth, then air the soil with a fork now and do this every couple of weeks till the start of March. In March I would hand sow grass seed by scattering it over the affected area, then hosing the area down lightly with water afterwards.

I did that last year and it looked bare for a while, but by May I could not tell what area I had sown.

many thanks for that look forward to trying it! fingers crossed

Also look for the cause of the dead patches. If drainage is a problem, best to fix that before you sow. If there is too much shade, choose a shade tolerant grass to grow.

and be gentle cutting the new grass to harshly . i used to cut mine with scissers but it was small . theres a big head sculpture and loads of great plants and well overstocked lol . some could say jungle like . its not a garden you can easily walk through realy . if you got to use a mower cut it long the first couple of times .