First find out why he acted that way. Is being mean part of his nature? You are lucky to have seen both sides of him early on in your relationship good and mean do you still want to be friends with him. How can you sure he will not act that way again.
hmm. you just forgive and forget.
Give him a panda
Please forgive me for doing the what I just did which i wouldn't dare remind you of, please forgive me mate.
If it is you that your friend cannot forgive, then give your friend space. Let a lot of time pass (weeks, or even months). If your friend still cannot forgive you then you need to face that and give up the friendship. Just deal with it; life will go on and maybe years from now you can re-connect. If you have a friend who cannot forgive someone else, just continue being friends and let your friend talk about it if necessary. You cannot make a person forgive someone. It happens over time, or it doesn't happen. You have to roll with it.
If you really want your friend to forgive you then do it face to face or do something nice to show that you are truly sorry and not just sorry when and where it is convenient for you.
no
f course
Yes you should but that doesn't mean that you have to put up with it. If they call you names intentionally all the time they aren't your friend.
Just say politely and respectfully that your're sorry. If he/she is your true friend, then they will forgive you.
You can't force another person to forgive you. The best you can do is sincerely apologize and hope.
It depends on what they did. If you feel you want to then maybe they should. If you forgive them and want to give them another chance then you should.
Forgive him if he is a friend, or doo something about it if he is not.