Ameri, the web provided by Fanning should help you. If not, ask someone to call DIGEMIN (do you know when they changed it?). My husband went in May, and it seemed straight forward, although we ask an attorney to do it because of times and availability.
Seb, it will depend on how you got the CE. If you are married to a Peruvian, your spouse has to write a simple letter saying you are still married and living together. Besides that you need to make a payment, have your tax up to date, present a recent original of your marriage certificate, copy of spouse's DNI and the signed form requesting the residency renewal. Also carry your Passport and CE, of course with a simple photocopy per document (they do love photocopies!)