Need to alter all the relationships (9,000) in a project

I have a schedule with around 8,000 inter-project ties. I need to change each of those ties to point to the same task nbr in a different project. So, if a predecessor currently points to task A100 in Project "Concrete", I want it to point to "A100" in Project "Concrete-6" instead. I can do the mapping...in fact I dumped the project to XML, did the mapping, and recreated the collection of links. I had some issues with XML, so I used XER-Parser to dump ALL the projects in both "collections" (e.g. "Concrete" and "Concrete-6"), then removed ALL the TASKPREDs (120,000)