change email address

how do you inform Ryanair of an email address change for a booked flight ?

http://www.ryanair.com/ie/terms-and-conditions#article3 :

3.3.2 If you have not provided us with a valid e-mail address, you should re-check your outward/return flight timings via the "Manage My Booking" facility on http://www.ryanair.com/ or with one of our call centres between 24 and 72 hours prior to scheduled time of departure.

If you really would like to notify them of the e-mail adress change, contact the customer service :

http://www.ryanair.com/ie/questions/contacting-customer-service