Why is it incorrect to use “how” before an infinitive here?

On a forum about English grammar, a user (a native speaker) wrote that the sentence below is not grammatically OK. Can you please explain to me why not?

This is the only chance how to win money.

Not only is this sentence grammatically incorrect, it doesn't portray whatever you're trying to say very well. I assume it's something along the lines of "This is the only chance we'll have to win money," but I can't be very sure.

The word "how" typically refers to the methodology involved in doing something. Asking "how" means you want to know the series of steps that occurred leading up to something else. The only non-interrogative usage of "how" I can think of off the top of my head is in a title, such as "How To Train Your Dragon," or in reference to a previously-asked question ("I'll show you how to do that.").

I can't give you a correct version of what you're trying to say without knowing more, though, since that sentence simply doesn't mean anything concrete.