People only change when (they) are unhappy with something or they're not getting the results (they) want in life.
There really is no way to ask or tell someone to change their appearance without appearing to want to "change" them.
Clearly his present appearance was good enough for you to make him your man. Very few people are walking around with a hand raised in the air screaming; "I'm looking for someone to change me!"
The vast majority of people want to be loved and accepted for who they are. How would you react if a man told you he wanted you should change your hairstyle and get rid of your glasses? dress a certain way, or have breast augmentation surgery?..etc
Suggesting "make over" to someone is the same as telling them they need to "improve" upon their appearance.
Only you know your man's personality. I imagine if you thought he'd be "receptive" to the idea of changing you wouldn't be trying to come up with a strategy to get him to do it without offending him.
There are only two ways to experience joy and peace of mind in relationships: We either get what we want or we learn to be happy with what we have.