Pat, if you have Acrobat 8 you can do what you want as far as changing all occurances of the company name. I just did this on a long document I had using the new "Redaction" feature. You start by doing a Search for the word you want to change, i.e. the company name. The Search box will list all occurances of the name. At the top of the search box select "check all", and at the bottom check "Mark Checked Results For Redaction".
In the Redaction properties/Appearance check the "Use Overlay text" box. Below that select "custom text" and enter in the new company name. You can then select "Apply Redactions" and bingo! All the company names are changed in the document to the new name.
I had wanted this type of feature for years as I deal with some confidential documents that I need to remove information from before I pass them along. The Redaction feature does just that.
Easy way: From Menu Bar choose : Advanced --> Image