Can anyone tell me how to change my profile picture?

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Apparently I joined this site three years ago, not that I remember it, but there I am, with my (old) phot and (old) address. I can't figure out how to change those details though, the edit profile page just gives me the option to change colours, not any of the content. Help would be much appreciated as I'm finding this site surprisingly counter intuitive to use. Thanks Gail