Hello,
Please read about theme update in our documentation -https://www.8theme.com/demo/docs/lifestyle/#theme_installation_and_upgrade
If you edited php files, I would recommend you to transfer changes into a child theme. Your Theme Options settings won’t be lost, but you can export them into file (Theme Options > Import/Export > Options > Import Export > Download data file)
Don’t forget to create a backup of your files and database before starting update process.
Regards