Changes to the pcdStartUp.properties

Hi,

I need to change PCD configuration parameters and looking in the help.sap.com (http://help.sap.com/saphelp_nw70/helpdata/en/2a/edece171d547449ab0e1d295f3b0bc/frameset.htm), found the following sentences:

"...

You make changes to the pcdStartUp.properties file on the J2EE Engine

...

PCD configuration parameters can also be defined as system properties. Settings that are defined as system properties always overwrite the settings in pcdStartUp.properties

...."

But there is no explanation about how to do it. Should I change the file in filesystem or do it in Visual Administrator (how)?

Thanks

John