The ToneWoodAmp update utility can be found at

This update utility can be used to update the firmware of your TWA to the latest version (2.69), to revert to factory settings, or to install Chorus. 

You'll need a micro USB data transfer/sync cable with a connector long enough to fit into the USB port on TWA underneath the output jack.

A USB cable with an 8mm tip will work. 

To perform an update, download, unzip, and open the TWA Update Utility. Power on and plug in your TWA via the USB port under the output jack, and follow the onscreen directions. 

Windows 7 or 8 users please note that you'll be required to manually install TWA's drivers to run the update. You can find instructions on manually installing drivers here.