a friend has been using a ouija board by himself and now has a spirit, how can we make it leave?

my friend has been using a ouija board by himself since july and has been hearing voices and has captured images on infrared film and his cat has been acting crazy, it will just jump for no reason and runs thru the house and hears the same noises as my friend. he says he has watched the cat watching something move thru the house. i have already told him to quit using the board by himself. i explained how using it alone makes you an open doorway for anything that wishs to come thru. i told him to get a white sage smudge stick and attempt to cleanse his house. should he destroy the board in order to get rid of the spirit? is there anything else we can do? any constructive help is welcomed, thank you