The 580 EX II went out again in 2023, after just 5 years with the new tube.  The 2nd tube replacement went a bit smoother.

The capacitor grounding pad in the 1st tube change was no longer at 330V.  It was now at 5V.  What was still at 330V was the pink wire.  This had to be discharged.

The service manual actually recommended discharging the now defunct pad.

Then the wires came off the PC board.

As recommended, the silicone band came off before taking the tube out. Then the tube came out with the wires.

The old tube still appeared viable.

The reflector showed progressive fogging, possibly from outgassing of the shrink tubes.

The new tube got point to point soldering instead of wraps of the wires around the terminals + soldering, as the previous tubes had.  It was slightly fatter than the previous tubes.

Then the tube slid back in without the silicone band.  It had to slide in from the left.  The tube + heat shrink was too fat this time, so the heat shrink had to be stripped off of the right side.

Then the silicone band went back on with much tweezing.  It had just enough compliance to get the wires through it.

Helas, it still no longer flashed.  This seemed related to the discharging pad no longer having 330V.

The focus aid still worked.