This asks for two passphrases. Give the password from the last step as the input passphrase and you are set. The "output passphrase" will need to appear in your jetty.xml config file as both the Password and KeyPassword of the SunJsseListener that will use the certificate.
We may also use keytool (starting form jdk1.6) to import pkcs12 file with the following command:
keytool -importkeystore -srckeystore jetty.pkcs12 -srcstoretype PKCS12 -destkeystore keystore
Step 4: Configure Jetty