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- Open Woffice-Intranet.zip, which is the main package you get from Themeforest.
- Find woffice-child-theme.zip, which should be in the main root.
- Upload in WordPress (Appearance > Themes > New > Upload) or by FTP.
- Activate it.
When you go back to the Themes page and click on the Child theme's "Theme details" button, you should see:
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