Once you download Music Data (tones, DSP settings, registration memory data, songs, rhythms) from this site, you can use Music Data Management Software for CTK-671 to transfer it to your CTK-671 on configure a custom keyboard setup that meets your particular needs.
Before trying to download Music Data, you should first read this section, which includes the following information.
Tone data that uses waveform data built into the keyboard
Setting data that uses the DSP built into the keyboard