To update to the current complete FreeDB , just reinstall the database (the old database will be overwritten).

FreeDB - Complete Offline Metadata File Approx 900MB

This is not an update but a complete installation of the current FreeDB.
The older database (FreeDB) will be overwritten with an updated metadata. 

To install (after downloading the file):

1.       From: Setup/CD ripping/FreeDB install/USB 1 (Locate the file)

2.       Takes about 10 minutes to install

Click to download the July 2016 offline metadata