How exactly i can access my Astral body in meditation?

Lord Buddha have access to unlimited knowledge, This information can be found in old Indian scriptures as well, that human body is capable to visiting to another planets with his/her Astral body (Suksham Sharir). Is there some particular way or do i need Guru for this particular thing ? Many Buddhist monk don't teach this, i am aware that Lord buddha himself have denied not to show any super powers. These Siddhi's (powers) may lead to Ego, But going in universe have always been an interesting thing for anyone.