Can you put this into different words or explain why the word "how" is used here?

There seem to be a few errors in this poem, either by you or the 'poet'. The word 'how' could easily be 'show' or even 'have'. Otherwise I'd say it was just some guy trying to sound smarter than they really are. Some old poems have uncommon uses for certain words, but the word 'how' in that sentence just doesn't fit or make any kind of real sense.