Which sentence is correct?

Ted and I cannot convince Steve to change, because he must first convince he himself.

Ted and myself cannot convince Steve to change, because he must first convince himself.

Ted and I cannot convince Steve to change, because he must first convince himself.

Among the choices given, the correct answer is:

Ted and I cannot convince Steve to change, because he must first convince himself.

The sentence uses the correct form and number of pronouns. "I" which is a subject pronoun is the correct form to replace a noun and "himself" which is a reflexive pronoun should be used referring to Ted, the subject and the object of the sentence.