Select association from the drop list.

Hit the option to select a file and choose the file you want to import and hit upload.

Once the file has been successfully uploaded, you will be notified. If there are any errors with importing, you will see the reasons in an error log, which will display on screen. You will be able edit your file.
Hit done when the file has finished importing.

The associations in the system will now be updated based on the file that was just uploaded.