[bashi]

You do not know why it is there. It might be there because it has a right to be. You might have allowed it, invited it or because of other karmic issues. You might not be aware of these relations, at least i wasnt.
So you basically nullify all agreements, understandings or relationships with it which might give it a right to be there. This is done by wilful mental declaration. Then you command it to leave you. During that communication you have to maintain a contact with it on that level. Otherwise it might not work.