Free Sydney Theme to Sydney Pro

Please can I have some help. I have been having issues with my website lately error codes and plug ins not working so I updated from free Sydney theme to pro in the hope that I would resolve issues but I am unsure how to transfer over my website to Sydney pro or Sydney pro to my website? Can I get a refund for the Sydney pro that I will not use?

Hello there,

Have you followed this instructions?

Regards,
Kharis