Restoring old Kamares

Hello all, I need some information regarding the restoration of old karmara that I have on Kythira. I have seen many of these restored on the island and it amazes me how well they have been restored. The information I need is basically builders, licences requirements and how do I go about it. Any information would be greatly appreciated and if anyone has gone through the process of restoring their own kamara I would love to hear your thoughts.
Thank you