Question: I have installed Crouton on my chromebook, with the standard unity desktop(Ubuntu 12.02).

However, I wish to use the Gnome 3 desktop environment. I cannot however install gnome-shell, since it requires me to change the DE from the login screen. Since I log in from the shell of chrome os, this isn't possible.

If I have gnome-shell installed, how can I change the desktop environment from inside Ubuntu, with Unity DE?

Answer: 
As you can see the package in your package manager, you should run the command below:

```
sudo apt-get remove master-pdf-editor

```
First search for the application name then remove it after:

```
apt-cache search master-pdf
sudo apt-get remove -purge master-pdf-editor

```

[![master-pdf-terminal-remove](https://i.stack.imgur.com/4LOVu.png)](https://i.stack.imgur.com/4LOVu.png)