You can't in Ubuntu. The launcher is a integral part of the Unity experience and Ubuntu. In the new 16.04 you will be able to place the launcher elsewhere. But the launcher will still be there. By the way: this method was chosen because it looks the best on ALL Ubuntu devices: from 4:3, 16:10 notebooks through to phones and is part of the Ubuntu path to convergence.
If you want another desktop experience you will need to install another desktop. The Mate desktop is a version that supports the old gnome2.
Random image from the internet with the panel at the bottom:
The way to add a desktop is by using apt-get to install it:
sudo apt-get install ubuntu-mate-desktop
After it is installed you can pick this desktop (and any other that is installed) at login. You will need to turn off auto-login. If you are satisfied with this desktop you can remove the old Ubuntu desktop with ...
sudo apt-get purge ubuntu-desktop
The same is applicable for any other desktop. A small list:
- Kubuntu, KDE desktop:
sudo apt-get install kubuntu-desktop
- Xubuntu, XFCE desktop:
sudo apt-get install xubuntu-desktop
- Lubuntu, LXDE desktop:
sudo apt-get install lubuntu-desktop
- Ubuntu GNOME, Gnome 3 desktop:
sudo apt-get install ubuntu-gnome-desktop
Technically you should be able to add ALL of them to 1 operating system and switch between them from login. But I would try to avoid it, it is likely software will conflict, and/or when removing it might leave traces, make the system unstable.
If testing is the goal (to decide what to go for): use a virtual box and install your operating system in there.
Here is how the login works (from linuxpitstop, theswitchtolinux has also got a good blogpost on it) :
In general it is best to re-install and stick to one desktop. That will remove all traces of the old desktop. Every desktop also comes with a different set of pre-installed software. Not all of them have "gedit" as an editor, not all will have Nautilus as file manager or Firefox as default browser. Some of these desktops focus on the lowest footprint possible so it will work on very old systems. That means less focus on perfectly looking software with all kinds of effects and features. So a focus on performance over a visually good looking desktop with lots of features.