First a rant - who is the wally that uses 'Tumbleweed' as a pen-name ?
It means that you can't search meaningfully on that.

And now .... her-indoors has got out ! Mistake. She got hold of the
Tumbleweed and didn't read the instructions.

The lawn is about 300 sq m (nominally 30 m long by 10 wide) and has
some 40 dead patches on it. What's the way to repair it please.

Thanks

Rob