How can I make my shirt look 80's?

I have a shirt that is made for guys. and I want it to look like its a girl shirt. and I'd rather go with that 80's look where the shirt just sits on your shoulders.
and I know your supposed to cut out the collar but I was wondering if there was anything else your supposed to do before I do it.

ripped sleeves or a shirt with a wide neck so you could wear like a wife beater underneath so the shoulders show

Yeah,Cut the collar wide,so it hangs off your shoulders.
Then weair a wifebeater or a different tank top underneath.

It would also be pretty 80's to wear a contrast color belt around your wasit with the shirt.