Okay, fixed. The program button is on the pc board inside. Use a knife or straight slot screw driver to grip the hex nut on the 1/4" input connector. Gently separate the case from the assembly (mine required additional cursing). Inside, under the tip of the connector, is a small button. Follow ...

Teensy prompts me to "Press Button on Teensy to manually enter Programming Mode." First, I thought Teensy was a program, not a device. Second, what button? I've got a MIDI Expression.