There is no place in the UI to find this. You can however, query the template table and look for that name. It would be a query something like this:
where PageTemplateWebParts like '%>Namespace.ClassName.TransformationName<%;
I include the > and < simply to ensure you're looking at the actual property name. You could include the whole property string:
If you're looking for just the listing transformation name. Once you have your WHERE condition set (be sure to check for a site ID or NULL if a multi-tenancy instance) you should be able to perform a
REPLACE on the
A couple notes:
1. Be sure to stop your instance before doing this update.
2. If you didn't stop your instance before doing the update, be sure to clear your cache on the server/machine prior to starting development again.