Here's a quick tutorials on how to change the default desktop theme in Ubuntu 11.10.
Before you start, Ubuntu 11.10 (Oneiric Ocelot) uses GTK 3 theme. Unfortunately, the GTK 2 themes won't work with this new version 3 of GTK. Make sure before installing a new theme it is compatible with version 3.
With that said, Here's how to install a new theme manually. The first step, will be to install the Gnome Tweak Tool.
sudo apt-get install gnome-tweak-tool
Now, from the command line, create the
cd ~ mkdir .themes
This folder will be used to put all the themes downloaded. Simply extract the downloaded themes into this folder. You should get something like this:
ll ~/.themes total 4 drwxrwxr-x 6 customize customize 4096 2011-07-26 14:25 DownloadedTheme
Now that the theme is extracted to the
.themes folder, open the Dash and find "Advanced Settings".
In this Advanced Settings, select Themes and select the theme under "GTK theme" you downloaded and apply.