How do you upload a custom avatar?

I can't seem to find out where to upload a custom avatar for myself. I looked it up and found a post providing the URL. That helped as I seem to be close to the right area, but I still can't seem to find out how to do it. The post also mentioned that you had to have atleast 50 posts (which I have passed).

Go to "Settings" on the top right and on the left menu bar, click on "Edit Avatar" under "My Settings".