Add GL account codes on Requisition Approval Notification

We have a business request to add some fields such as GL Account Codes, project number to the Requisition Approval Email Notification. One way of doing this is to customize PL/SQL package PO_WF_REQ_NOTIFICATION, procedure get_req_lines_details_link by adding additional fields along with HTML tags. My problem is that the changes I made to this package/procedure do NOT show on the email notification. We bounce the application server, flush share pool, etc.. Still not showing the changes. I see some other users also had similar problem. Does anyone know the solution, or workaround ?