Air France Frequence Plus - AF booking engine: changing a booking class.

I am flying CDG-ATH. outbound I get offered N class, inbound W class. I wish to book my outbound flight in W too, to get more flexibility. I read in a thread here, that it was now feasible, BUT I have not understood how to do it. Can anyone help?

for CDG ATH, the fares are:
170 EUR in N
220 EUR in E
350 EUR in W

why do you want to pay 90 EUR more for W when you could just get E for 25 EUR more, with the same flexibility.

usually, in the booking process, you need to chose flights by fare, then select the price "changes allowed at a charge" or "modifiable avec frais"and you will be automatically in E or higher booking classes. There is a bug in the booking class displayed in the last screen, confirm the booking class by checking fare rules or conditions du tarif, the fare basis should be displayed in the first line ESTAYFR WSTAYFR.

you can finally crosscheck that with the base fare: 285 EUR => E+W etc.