I don't know how to update my Blog profile photo!

Willie on a boat

This is my first Blog post. I simply want to upload a photo to my profile page but somehow I don't know how I can upload a photo here without publishing it as an article. Eventually my first post here becomes this lousy one which the sole purpose of its existence is to store my profile photo.

I think there should be a better way to do this. If you know, please tell me. Thanks.