Please help me get rid of these nasty big mushrooms in my lawn they're
ruining it!

Pick them and eat them.

What about the poor garden gnomes that live under them?

Sadly, I think it is illegal to eat them, although (allegedly) they are very
tasty if deep fried.

LOL good one

My other half picked some mushrooms from our garden yesterday and ate
them, said they were very good
kate