I have not tried it myself, as I have automatical login enabled; however as I understand you should make the following:
(do it at your own risk; please don't do it if you have data on your computer that you don't want to lose.)
Open terminal and type:
You will be asked for your password.
sudo cp /etc/gdm/Init/Default /etc/gdm/Init/Default.backup
gksudo gedit /etc/gdm/Init/Default
The first line makes a backup of the file we are going to edit. The second line will open the shell script named 'Default' located in /etc/gdm/Init in the Text Editor named gedit. You have to edit that file.
You will have to add the 2 words 'exec onboard' before the last line. The bottom of the file should look like:
Save the file and close gedit.
exec onboard &
Afterwards, open the menu:
The window containing the preferences of the Login Window will open. In this window do the following:
- choose the tab named 'Local'
- click on the popup at the right of 'Style' and set it to 'Plain'. (mine was set to 'Themed')
- close the window
If I understood the indications in the other thread correctly, now you should see onboard at the login screen.