The input jack fell into the amp. I hear this is a pretty common problem with the Valvtronix series. Can anyone tell me the quickest way to fix this? What part exactly do I need to take off to get to it?

Thanks a lot.
It is a common problem. Mine fell in on my AD30. The whole amp section needs to come out to get to it. Loosen the sides first, loosen, don't take the screws out yet. Remove the screws holding on the back and genlty pry out the back. Now support the amp with your hand and remove the screw holding it in. That's how I recall doing it, it was some time ago. Hope that helps. You might want to find a metal nut to replace the plastic one.