That obviously hasn't a literal meaning, it has a really deep meaning, and you should read the context for realizing what it means by itself and not literally.
Anyway, if you want to know the meaning in english of that phrase, the correct way to write/say it is this:
"a plumber who arrives in France with a wrench in his hand to fix pipes"
From my point of view, it means that a manfrom England (that's why it's "llave inglesa"), arrived to France with the intention of doing something revolutionary.
I hope I'd helped you :))