Its time to change the tubes , I tried to open the back panel but after opening all the back panel screws and the two side screw
The panel is not able to open .
I have a new tubes reference to the amp spec.
Please advise how can I open it and replace the tubes ?
if you have a special instructions it will help .
![Dunno (???)](./images/smilies/dont_know.png)
![Dunno (???)](./images/smilies/dont_know.png)