Hi Eddie - importing them one at a time would be a nightmare! You should definitely use the Batch Import method. Here is our procedure:

Importing Translated Files in a Batch
The fastest way to import translated files is using the batch import method. Batch imports automatically place the objects in Review Translation status.
To import the translated files in a batch:
1 Place the translated objects for import on the LCA server in the Data\BatchImport\ImportTranslations\ToBeImported folder.
2 In the LCA web interface, click the Tools tab.
3 Click Import Translations in the navigation pane.
4 If needed, click Remove Log to clear information about previously imported objects.
5 Select Auto refresh, then click Start Import.
The object moves from the In Translation inbox to the Review Translation inbox.
There should be zero items left in the folder when the import is complete. If there were errors, you can view them by clicking Show Details. 

IMPORTANT! the file name must be complete in order for the file to import using this method. The convention is: Name=GUID=version=language=resolution (this is what you get if you download the file from LCA to save it to your hard drive somewhere).

For example: compareQuery=GUID-23290202-A1FD-4607-B077-C81BDED945BA=1=FR=Low.png

Hi Eddie - importing them one at a time would be a nightmare! You should definitely use the Batch Import method. Here is our procedure:

Importing Translated Files in a Batch
The fastest way to import translated files is using the batch import method. Batch imports automatically place the objects in Review Translation status.
To import the translated files in a batch:
1 Place the translated objects for import on the LCA server in the Data\BatchImport\ImportTranslations\ToBeImported folder.
2 In the LCA web interface, click the Tools tab.
3 Click Import Translations in the navigation pane.
4 If needed, click Remove Log to clear information about previously imported objects.
5 Select Auto refresh, then click Start Import.
The object moves from the In Translation inbox to the Review Translation inbox.
There should be zero items left in the folder when the import is complete. If there were errors, you can view them by clicking Show Details. 

IMPORTANT! the file name must be complete in order for the file to import using this method. The convention is: Name=GUID=version=language=resolution (this is what you get if you download the file from LCA to save it to your hard drive somewhere).

For example: compareQuery=GUID-23290202-A1FD-4607-B077-C81BDED945BA=1=FR=Low.png

Is there a tool that you use to help automate the file renaming to match the image names in the CMS? 

No... but one way to do it is to do this:

1. Export the French pub (for example) after it's sent to translation and the objects for localization have been created by the CMS. (This exports all the files with the full file name.)
2. Separate out the graphics. 
3. Overwrite any that are English with the localized equivalent.
4. Batch Import them.