What to say?

You don't, she learns that on her own, all I can say is just keep trying.

Be sweet without smothering her. If you really care about her and are 100% committed to making her fall for you, find out what she thinks all other guys are like (if you don't already know) and don't do those things.

If she's been burned by another guy, she may take a lot of time to come around....and even more time to trust you. But hard work, persistance, and patience should do the trick.

Just talk to her and let her see you! Don't go at the situation with negativity. Just be real and yourself, and if she's a good woman, she will see you for who you are. Best of luck!

It takes time and patience to win over a girl who has been hurt before. If you really love her, you'll give her that time and she'll learn to trust and love again.

Actions speak louder than words. You know her sweet spots; what she likes and doesn't like so think of some sweet ways to surprise her and show her how you feel.

Well most guys go through that bridge. Trying to show that they are not like all men :) Which is in a way true, everyone is unique. To get more answers, I think you should mention why doesn't she believe you or does she even know that you love her? It's pretty tough to get answers to a very general questions. But to give you an answer, letting her know that you are interested(like/love) in her and then letting her(by giving her space - no pushing, calls etc) decide what she wants is a good way to get respect from a girl. Because you revealed your thoughts and you respect her as she will make the decision. She will get that!