How to EQ poorly recorded vocals where the tone is all over the place?

Hi Chris, hope you’re well. Sam from Laos here, we met at your seminar in Bangkok organized by Mr. T several years back. I have a question, how do you deal with poorly recorded lead vocal, by poorly recorded I don’t mean the singer is pitchy but rather he/she is moving all over the place while singing into the mic, so the recording has unbalanced tones through out the track. Thank you, hope to meet you again in your future seminars.