Installation rescue

Hello,

I could just try another installation but curious how to rescue mine. I'm writing from a linux Mint previous installation on another partition of the same disk.

The installation from a live iso (on a USB stick) went OK until the moment of apt configuration. I said I wanted to stay with the disk and not from a mirror and the system blocked. From a console (Alt + F2) I asked for a reboot but now I have plenty of files but no graphic access. I have root access. How can I restart the installation process ? How about fixing a mirror for apt from where I ended ?
I can't provide informations directly from this Kali installation but interested by any check I could try.