removing case tube from 2541.80 (196.1523)

If you have the replacement case tube, how it attaches to the case and how it is removed should be pretty self evident just by looking at the parts. Post a photo of the case tube you have...

As you can clearly see it's a pressed in tube - if it were threaded there would be threads on the smaller diameter.

I would strongly recommend that if your watchmaker is not comfortable removing this tube, then you should find someone that is. Having said that this is the way its done:

1 - Remove the movement from the case
2 - Remove the bezel from the case
3 - Remove the crystal from the case
4 - Heat the case adjacent to the case tube using a small torch
5 - Using a small easy out that fits into the case tube, turn the tube CCW after heating enough the break the Loctite bond
6 - Clean the case
7 - Apply Loctite retaining compound to the case tube
8 - Press the case tube into the case
9 - Install the crystal using a new crystal gasket
10 - Complete the assembly of the watch, using a new crown - always change the crown with the case tube.

Cheers, Al

It takes some time to change, but I would not call the job difficult by any means. The biggest thing is to not try to take short cuts. If you snap the outer part off the tube off, leaving the pressed in part stuck in the case, it becomes a much more involved job...