Batch Update of Existing Items

My co-workers and I have uploaded thousands of items into an Omeka database, version 2.1.3, using the CSV Import plugin. Each item has metadata and a single jpeg file.

Now we need to add a second jpeg file to hundreds of the items. The new jpegs are landscape-orientation copies of existing portrait-orientation jpegs. (I gave up on CSS transform: rotate due to browser incompatibilities.)

Is there a way to do a batch update of the existing items using the CSV Import plugin or by some other means? I have already tried uninstalling the "official" version of the CSV Import plugin and installing a fork (https://github.com/Daniel-KM/CsvImport) which I thought included update support but it seems that the Omeka 2.0 version of the plug-in lacks update support.

Thanks in advance for any help!

I think your best bet is probably going to be to undo the first import, then do a second import from a CSV with the second file included in it.

I am also trying to use this CsvImport fork. Is there anywhere I can find documentation on how to make my local copy 2.1.3-compatible?