Thank you, my kobo is saved!
After the operation, I tried to run my reader before remounting the casing. I discovered that the touch of the screen was no more working. But it reworked once the casing was in place... I imagine that it comes from the IR technology used for the screen?!
To save the image on the microSD card, I only used the sofware indicated somwhere in the discussion about the memory update of the glo:
http://www.alexpage.de/usb-image-tool/download/
It is easy to use, and necessary, because the soft indicated in the original post is no more available.
Pierre