The plugin can be installed entirely from the WP Admin or Manually, just like any other plugin.

From WP Admin:

1. Go to WP Admin – Plugins – Add New.
2. Search for “Synchronizer Addon For WooCommerce to Google Spreadsheet”.
3. Install the plugin and then Activate it.

Manual Way:

1. Download the plugin zip file.
2. Extract it.
3. Upload the plugin directory to wp-content/plugins.
4. Activate the SheetSync for WooCommerce Stores from WP Admin – Plugins