Renewing from Gandi's home page
From Gandi.net's home page, click on the “Renew” link that you see under the domain name registration form (or click here to access the Gandi renewal interface directly):
You will then see the following form:
To renew your domain, enter the domain name(s) to be renewed in this box and click “Validate”. If you have several, just list them, one on each line.
You will then be taken to the next step, where you validate your choice and choose the number of years if applicable.
Proceed to the next step: chosing the number of years to renew