While you can associate more than one email address with your Facebook account, you must designate one address as the primary address that receives Facebook notifications. Before you can use a new email address, you must confirm the new address by clicking a link in a message that Facebook sends to you. To change your Facebook email address, add a new email to your account, confirm it and then designate it as your primary address. You can leave your former email on your account or you can remove it from your profile.
Making the Change
Click the triangle at the top right of any Facebook page and choose "Settings." Select "Email" and choose "Add Another Email." Type the new email address in the box and select "Save Changes." Log in to your email account and click the link in the confirmation email message from Facebook. In Facebook, select "Email" again and click the radio button next to the new email address you want to use as your primary address. To delete an old email address, click "Remove" to the right of the address. Choose "Save Changes" when you've selected the correct primary address.