An exorcism can be defined as ?the expulsion of Demons or other evil spirits reputed to have taken possession of a person, place or object.? So in theory anyone can preform them. Lorraine Warren, a gifted clairvoyant and wife of renowned exorcist Ed Warren, once said that one only needs faith behind their actions for them to work and she was a devout Christian.
A word of warning, exorcism can be very violent procedures and people can get hurt (Lorraine herself once was very badly injured). Do not preform one under uncertain circumstances as you could hurt yourself or the other people present. If you truly think one is necessary please research what to do thoroughly and try have another witch there to help you.