How do you retrieve the appropriate dependency using RetrieveDependenciesForDeleteRequest

I'm trying to delete a managed solution but keep getting the following error: 

The SdkMessageProcessingStep() component cannot be deleted because it is referenced by 1 other components. For a list of referenced components, use the RetrieveDependenciesForDeleteRequest.

Now the RetrieveDependenciesForDeleteRequest needs the type code for SdkMessageProcessingStep which is 92 and an objectId. But I don't know what this object id is because the error does not provide it. What is recommend approach to diagnosing such dependency errors?