How and where do we add fields to oracle purchasing requisition workflow email.

Hello, I am a first time poster to the forum, I have never really used the community forums, only my oracle support for creating SR's, but I figured I would give this a shot.

We are on Oracle APPS 11.5.10.2 preparing for the upgrade to R12.  We are running on linux server.  We have been using the purchasing module now for several years, and have all of our hierarchy setup and working great.  All we want want to do is add a flexfield (Work Order No) that we have added to the requisition lines onto the approval notification that gets emailed to all the approvers.  We have downloaded and installed workflow builder 2.6.3.5, but we are finding it a bit overwhelming to modify this workflow.  We feel like we have identified the correct workflow