It is not rarely heard that sb said:Could you tell me how to ....? In ielts test book, you can still find the same sentence. I promise it is right .
I have said 3 millions of times that 'HOW TO' is not a correct way to make a question. Once again, please remember what you should say is 'how do..', 'how can/could', 'how is'....I promise you I won't say that again.