I'm looking to reinstall ubuntu (actually, switch from ubuntu to xubuntu) and currently have full disk encryption enabled.
I downloaded xubuntu to a USB and booted of it; when going through the installation process it never asks for the decryption password on the drive and tells me that there isn't an existing installation... how to I install without over-writing my current data?
Xubuntu says there is no install because your disk is encrypted, so the Xubuntu installer can't tell there's an existing Ubuntu install, and doesn't know it can be decrypted. Op success on that front.
The best way to swap from Ubuntu to Xubuntu is just to install the Xfce desktop on the existing system.
Once you're happy with the xfce desktop and have confirmed it works, you can optionally go the extra mile with sudo apt-get remove ubuntu-desktop, although I personally would keep it installed as a backup desktop.
