You can import resources to replace your extension's source files with those from another extension.
Click Menu in the upper right corner and select Import.
In the Import Resources dialog, drag and drop the ZIP archive of an extension that you've previously exported, or click the drop area to locate the archive on your local system.
To replace all existing files (and prevent duplication), select Delete existing files and resources.
Click Import.
The resources are imported to your extension's root directory.