If you are going to modify components, you first upload the handlers for those components before creating or configuring the components. You only need to upload the user-defined handlers for the components that require them. For example, if you are adding your own validation step, you need to upload that handler from the Actions page of Handlers (as described in steps 1 through 4).
You can modify fixed workflows and actions and create new actions. You modify these components by the handlers you associate with them.
To upload a handler, perform the following steps:
The list of handlers currently defined for that particular component is displayed. Notice that handlers provided by WebSphere Partner Gateway are listed. They have a Provider ID of Product.
After a handler is uploaded, you can use it to create new actions and workflows.