The WebSphere 5.1 plug-in is contained in the SUNWspswas.msi file.
Move to the directory containing the sun-spswas-3.0.msi file.
Double-click the sun-spswas-3.0.msi file.
The Installer GUI start. The JAR file is copies to the C:\Program Files\N1 Service Provisioning System\plugins\com.sun.was directory. The upgrade JAR file is in the C:\Program Files\N1 Service Provisioning System\plugins\com.sun.was/Upgrade directory.