Thanks a lot Pepe

This is exactly the idea I had.
Repair-Bde:
I confirm that the metadata written at the beggining of the external drive is safe a accessible from repair-bde.
Command used: Repair-bde g: h:\dataimage.img -rp 445753-050908-116633-034606-691966-304216-490831-695222 -f
However, when trying to force the decrypting using this command, I got an error at 5%. 5% seems to be the point where the encryption stopped. (Size of drive 500Go - usb only) I assume that the remaining 95% are not encrypted.
Q1 : How can I access to the remaining 95% of the data?
In addition to that I mounted the image using Daemon Lite, I got a windows error: "Windows cannot access the drive, it can be damaged"
Q2 How can we access to the image created by repair-bde (error above) ? representing 5% of drive
Q3 Dislocker is running on Linux & my machine has windows. Is there a way to run disloker online on a Linux machine, I remember I did it some time ago.
Q4 Which tool should I use to make an image of the drive in current state including the meta data ? Macrium is ok?
I found the tool TestDisk. I am going to investigate dislocker option & find a way to run it
Thank you for your help I will update you,