Using the MACRO tool.I need to modify tags and subfields to new information(migrating and vendors havn't caught up yet)So I was thinking MACRO - but I don't see how to "modify"  I see ADD949 - needs to be 952specific subfield and data that needs the subfield only changed...  Thoughts?  Documentation talks about subfield and adding, but don't see mod info.  An example would be great.b30126025890010 - pd741.597 ULT - op19.99 - gsIngram - el001 - aDavid Schuster