Thank you mikakunin.
The problem is that my mini pc (a Minisforum GK41 with intel celeron) with 5.27 version halt on an error during the boot on USB key : “Connection with X server refused”. And i don’t know how to bypass that error…
So i cannot update from an USB device.
Making a fresh install on another disk is not possible, it’s not like a Rapsberry, batocera is installed on a hard drive, not a flash card.