Hi joomleb,
Memberships already have at least a 20% discount on renewal, if you renew between 60 days before your membership is due to expire, until up to 30 days after it has expired. Once we implement the renewal feature, this may go up to 25%. Please see "what about renewal rules?" on this page:
http://www.seblod.com/resources/faq?cck=seb_faq&seb_faq_type=memberships&boxchecked=0&search=seb_faq&task=search
Right now there is no renewal button on the website, however if you want to take advantage of this offer today, please buy a new membership and we will update your existing subscription manually.
Thanks,
James