How do you do this?

When someone asks you a question, for example, 'How do you do this?', Do I reply back in second person or first person?? Since the question is asking about 'you', should 't it be in first person?

Question: How do you do this?

Answers:
1. You must be very steady with your hands.
2. I must be very steady with my hands.

For the answerers above, does it matter which one I use?? How come you can use second person when the question is asking about you??

Sometimes "you" means "you," and sometimes it just means "one, someone, anybody."  If the person is really asking about how you do something -- for instance, if you just showed them something complicated that you made yourself  -- then you would answer with "I."  ("How do you get the ship inside the bottle?"  "Well, I assemble the entire ship outside the bottle, with special hinges so that I can fold it flat...")  If the person is asking a general question, you would answer with "you," meaning "one, someone."  ("How do you find something on the internet?"  "Well, you can use a search engine, like Google.")

Does that help?