% sudo apt-get install xserver-xorg-lts-trusty
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 xserver-xorg-lts-trusty : Depends: xserver-xorg-core-lts-trusty (>= 2:1.11) but it is not going to be installed
                           Depends: xserver-xorg-video-all-lts-trusty but it is not going to be installed or
                                    xorg-driver-video
                           Depends: xserver-xorg-input-all-lts-trusty but it is not going to be installed or
                                    xorg-driver-input
                           Depends: xserver-xorg-input-evdev-lts-trusty but it is not going to be installed
                           Recommends: libgl1-mesa-dri-lts-trusty but it is not going to be installed
                           Recommends: libgl1-mesa-glx-lts-trusty but it is not going to be installed
                           Recommends: xserver-xorg-input-all-lts-trusty but it is not going to be installed
                           Recommends: xserver-xorg-video-all-lts-trusty but it is not going to be installed
                           Recommends: x11-xserver-utils-lts-trusty but it is not going to be installed
                           Conflicts: libgl1-mesa-glx (>= 0~)
                           Conflicts: libgl1-mesa-glx:i386 (>= 0~)
                           Conflicts: libglapi-mesa (>= 0~)
                           Conflicts: libglapi-mesa:i386 (>= 0~)
E: Unable to correct problems, you have held broken packages.

sudo apt-get install -f

sudo apt-get dist-upgrade

sudo apt-get remove xserver-xorg-lts-saucy
sudo apt-get install xserver-xorg-lts-trusty

sudo do-release-upgrade

sudo apt-get install ubuntu-desktop

sudo apt-get install ubuntu-gnome-deskop

sudo apt-get install xserver-xorg-lts-trusty
    xserver-xorg-core-lts-trusty
    xserver-xorg-video-all-lts-trusty
    xorg-driver-video
    xserver-xorg-input-all-lts-trusty
    xorg-driver-input
    xserver-xorg-input-evdev-lts-trusty

sudo do-release-upgrade