As promised earlier in Tube Amp project, the photos.

How to do it:

1. Remove the 4 screws at the bottom
2. Remove the tube by whipping it out using a flathead mini screwdriver
3. Place the new tube in the socket, try to avoid handling the tube with your hands

Im going to make a cheap but wicked tube preamplifier by replacing the tube inside an ART Tube MP.
The replacement tube will be an Electro-Harmonix 12ax7 gold-pin edition ECC83 tube.

The total costs of this project are just below 50 euro.