to flash your nokia mobile phone,you will have to take it to a mobile phone repair shop as special kit is used for this purpose and is done by qualified personnel. If you want to reset the mobile phone to factory default you can make it by following link below from faq which will guide you for the process:
Hi my is Gibo I HAVE A NOKIA 5130 EXPRESS MUSIC FOR SOMETIME NOW ANY TIME AI PUT IT ON, ITS TELLS ME (CONTACT SERVICE)WHAT DO I DO NOW?PLEASE HELP ME.THANKS.