Thank you all for your responses. I have to explain myself.
I love my Thiel CS 2.3. Truly. I have had many speakers in my life, these are among my favorites.
My problem is that one of them suffered a very bad fall because of a child. The woofer and the tweeter are badly damaged.
I contacted Mr Gillum who offered to redo my tweeter. I found an OEM Boomer in Germany. However, and this is my real problem (don't laugh) I AM FRENCH
Between the cost of the repair, the cost of transport, the cost of customs, the price of the OEM woofer, I'm not far from buying myself a new pair...
A person sells a pair of CS 2.4 tweeters not too far from my house, and since they have the same shape (but not the same magnet) I wondered if the modification was possible..
Now, if that can't be done I will have to find an alternative solution.
If you know someone selling a cs 2.3 tweeter... I might be interested too.
Anyway, thank you all for your help, it's super nice