@Cerbera
Thank you very much for the answer, it helps me a lot, very detailed, and efficient, thanks to the gif I understood the process, you must have guessed I'm not a modeler, this is an old model found on Sketchfab, I mainly use Cinema 4D to make renders.
You save me a lot of time, if there is anything I can do in return don't hesitate to ask me.
Best regards.
(Your technique works very well, but afterwards I did it manually with the "poly pen" tool to get something really clean.)
It took me 2-3 min, but the result is perfect!
It was really what I wanted 😉