Easily ? You don't, with the most common azerty keyboard you have to use : Ctrl+Alt+7 Shift+A. That's why there is a new standard for azerty keyboard the "NF Z 71-300" that is better with accent and stuff like æ,œ,Æ,Œ,«» etc.
What's weird is I sometimes, even 10 years ago, would get an email from people in France, and it would have an accented A. Like, how did they do that..