Where would I start to review how to modify a custom PO SSRS report to change the disclosure wording section? Do I need SSRS installed or what is the high level steps I would need to modify a custom SSRS report?
Most people use SSRS Report Builder and put the Disclosures there.
You could just use Report Builder after you log into the SSRS server. Though Visual Studio is much easier to use. You’ll login to the server, go to Reports/Custom Reports and locate the report. Then either download the RDL file and use Visual Studio or modify it in Report Builder.
Sorry, it turns out to be a Crystal Report .rpt file. How would we edit a crystal report or do we need to install the Crystal Report Builder application also?
I haven’t used Crystal so I can’t help with that. 
Yes, to edit a Crystal Report file you’d need Crystal Report Builder.
From what I’ve seen this will require a crystal report developers license also? I’ll have to take a look once I get it installed.
Correct… but if you’re installing from your E9 (or earlier) CD, that license key will still work.
Your heading to this is for E10/SSRS.
If this is for Crystal, yes, you will need Crystal Reports Designer. Version 2008 is best for Epicor 10 (assuming that is what you are using still).
However, if you have to edit the report anyway, have you thought about moving this report to SSRS now that you are using Epicor 10?