Hi Marco,
Goto the FRDM-KL03 product page:
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=FRDM-KL03Z
Click on Downloads tab:
Then you can download a separate KSDK installer for Linux or Windows.
I did the Windows version as FYI.
Install the KL03 KSDK (defaults to c:\Freescale folder).
I told the installer not to update the Windows path when asked.
I opened KSD1.1.1 and pointed the Workspace to the root folder of KSDK for KL03:
i.e. C:\Freescale\KSDK_1.0.0-KL03Z
I then used the Help-->Install New Software…
Click Add button then click Archive and point to following folder:
C:\Freescale\KSDK_1.0.0-KL03Z\tools\eclipse_update
Follow the wizard to install and agree with the legal stuff.
This will add in the KL03 Freedom to the Boards and Processors optioned when doing a File--> Kinetis Design Studio Project.
In December when KDS1.2 is released then KL03 will be integrated with it and not be a standalone install.
Regards,
David