I killed an Arduino BT by giving it too much power. Can any of the parts be salvaged? Can it be repaired by replacing a part?
Unlucky. What power did you apply? Did anything smoke or pop?
As this board is predominately surface mount, I doubt they'd be anything that can easily be rescued.
If the failure was such that the 3.3V supply didn't pass anymore than 3.3V to the Bluetooth radio, you may be able to desolder and re-use that, but it looks tricky to do.
You may well be able to repair it - it depends what failed and how - and how good your eyesight is.
Mike