How to perform a seance?

a few of my friends and i like to sneak out at night and tp pll. to keep it nto as boring we thought of doing a seance with a few other boys in my neighbor hood. there is a colda sac in my neighbor hood that doesn't have a thingy in the middle its just a circle we were thinking about doing it on there. where there isnt any gr incase we knock over a candle or something. we have looked at different web site and diceded to use a gl cup in our seance. we are going 2 bring a rosary and say a prayer before the seance just as extra pretection. we would like 2 know the stepps and any other materials needed to complete the seance. thanx!