I tried several methods.
sudo apt-get install xen-toolsis installing at least two packages but cannot configure / start them for unknown reason.
Using the iso provided by Xencenter (developer help page)
mount /dev/xvdd /mnt
End up this way
mount: special device /dev/xvdd does not exist
Using the iso provided by Xencenter (xen ochestra help page)
mount /dev/cdrom /mnt
bash: /mnt/Linux/install.sh: No such file or directory