Apple have a guide on it here: https://support.apple.com/en-us/HT204478 https://support.apple.com/en-us/HT204478 One thing to bear in mind is Photos will crea

Apple have a guide on it here: https://support.apple.com/en-us/HT204478 https://support.apple.com/en-us/HT204478 One thing to bear in mind is Photos will create a new photo library, leaving the old one untouched. The metadata will still be there, but good luck getting it out.