Open "Contacts" app : - tap on , - tap on "Settings, - tap on "Import", - tap on ".vcf file" or "Contacts.vcf", - select "Device", if needed,* - tap on , - select SD card, - select the file to import at the bottom of the screen : "contacts.vcf".
NB : The contacts list is fully backed up. It is not possible to back up a contact separetely. At the insertion of the SD card, do not format as internal storage in order to access files and contacts saved.