Install SOA 12c

Download the SOA 12c from the following link

http://www.oracle.com/technetwork/middleware/soasuite/downloads/index.html

The best part here is that you need not separately install Jdeveloper as the SOA 12c comes with Jdeveloper. A lot of other features have been also added in the new 12c such as now you dont need Eclipse for OSB development, you can develop your code in Jdeveloper itself

Once you have downloaded your code.

Extract the code and run it using jar as shown below