Unless you are somewhat already trained in some system of magic, I do not think there is some "exorcism recipe " that someone could throw together for you to use that could work. I could be wrong though, exorcism isn't a particular interest of mine.
If you sincerely believe you have a need for an exorcist, then you should ask a nearby diocese of the Catholic Church, if you have one.
In many places(Ireland for example) each diocese is required to have at least one exorcist trained.