Hi @Patriot74, welcome to our forum!
Your question has been translated to English as this is an International forum, please post any replies in English and it will be easier for me and other users to assist you.
Do you know how the contacts are currently stored? If you have them stored on your Google account you don't need to back them up as they will appear in the device when you add your Google account after the reset.
There are other options as well and you can find more information about them on the link below.
https://support.sonymobile.com/global-en/xperial2/userguide/backing-up-and-restoring-content-on-a-de...
I hope that helps! 
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