Alan Ratcliffe wrote
Warren's closest - get in any position where they will need to meet you. Even then, you are limited by etiquette - don't think a member of the road crew or promotions company can sit down with Slash and have a nice chat about guitars over a beer. Your best bet would be to manoeuvre yourself into a position where it's your job to talk about such things with stars - i.e. a music journo.
But seriously, what did you expect? >☹ If it were easy, there would be many thousands of fans who could get access to these folk and the artist's life would be a living hell.
Even as an opening act you would probably be excluded from their area due to you being lower down the food chain...I guess...