Depending on whether or not you have contact, here are some ways you can let him know you’ve changed. If you see each other occasionally, you can show him with your more beautiful energy and by the way you communicate with him. Or, if you’re emailing, you can say it in writing.For these situations, you can let him know the things I recommend below over several meetings or emails. If you are having no contact, you can write a letter, but not in a way that sounds like you’re trying to get him back, just letting him know how you’ve seen how it could have been and wish him well.