How can I edit PDF reports such as sales invoice? Specifically I would like to remove the discount field.

I have researched on the subject for months and found that many have experienced the same issue of not being able to connect to Open ERP Server in Open Office . I am aware of open office and perfectly followed the instructions to connecting Open Office to OpenERP however when entering the required data to connect to Open ERP Server, I get an error message. I downloaded older versions as instructed, I tried various entries based on different posts I read but to no avail. Can someone please give me very detailed instructions on how to make it work? It is becoming increasingly frustrating.