On my screen, it's upper right. Interesting....In the upper left you should see your name, inbox, alerts. click on your name and a window will open with various preferences, one of them being your signature.
@Mary Jo is using the 'Mirror Mirror' theme.On my screen, it's upper right. Interesting....
Delete the old one (backspace over it), and copy/paste the new one.I go in to edit signature but how do I replace the old picture with a new one?