Microsoft has a KB to describe how to update the Microsoft Dynamics CRM Web site port after you install Microsoft Dynamics CRM 4.0
Today I had to change the port number from 80 to 5555, however after following those steps, I can't run CRM reports. In the event log, it says: Error 19968 Web service request ListExtensions to Report Server http://crm/ReportServer/ReportService2005.asmx failed. Error: Unable to connect to the remote server
I have noticed that the virtual directory: ReportServer and Reports are located under the CRM website, so these config information needs change too.
There are extra two steps if your SRS is running under the CRM website:
Disable Organization >> Edit Organization >> change the SRS Url >> Enable Organization.