Hi Pilou, you can do that with the Trim command using the mutual trim option.

Select both objects before running Trim.

The prompt will say: "Select cutting objects or Done for mutual trim". So in this case where you want the objects to be both an object that is being trimmed as well as a cutter for the other, push the Done button (or right-click in a viewport) without selecting anything.

Then pick the pieces to discard and you will have your result.

Here is a demo:



- Michael