Keep your product up to date to receive new free features
Connect the two earphones in stereo mode, as described in the Quick Start Guide, to a playback device that has a stable Internet connection.
Then open the MIY app (from version 2.6.) and connect the earphones to the app there as well. Make sure both earbuds have at least 50% battery each. If new software is available, this will be displayed. Click "Update", then click "Install Now". A progress bar shows you how far the update has progressed. When the installation is complete, the earbuds will restart automatically and you will receive a success message.
More information about the sound personalization can be found here: How does sound personalization work for the Free BYRD?