Changing V1 preamp tube is risky

I changed the V1 preamp tube (put that huge cover back also) and it was not easy. After that only hum could be heard from the speaker. I removed the V1 tube and it looked fine. I put it back (but not that huge cover) and still no sound. I removed the chassis and it is ridiculous how difficult that was. Then I saw that V1 glass was broken and that white stuff was on the top of the tube. Then I changed V1 tube and everything worked again. I must make hole to wood underneath the front grill so that V1 changing would be easier.

Very tricky job to change v1 without removing chassis. Even in the combo it's difficult.

I have not removed the chasis ever in my 5+ yrs of owning it.. here is how you do it.. for amp head only.

Step 1 : Turn the amp upside down and let it sit such that the tube sockets point up.

Step 2 : Remove all power tubes n rectifier tube

Step 3 : Reach in with hands and slowly pull out V1. Remember the pin spacing when you take out the v1 tube.

Step 4 : Put in the replacement tube with the correct pin spacing as when you took it out in step 3.

I remember seeing a youtube video on this. Let me put in a link to it later ..