You will have to tell us what you are actually trying to do because your questions make no sense.
It’s becoming more and more like this kind of question:
Tell us what you actually want to do with this information and we might be able to help. You certainly DO NOT want to get a vector from a quaternion. What would you possibly do with it?
You “might” want to transform it… but we don’t know because we don’t know what you are actually trying to do. What is your end result?