If you want the Attachment file name to be updated in the articles. below are the list of steps:
Step1 : If the articles are published you have to create a draft articles for each published article manually.
Step2 : If the articles are draft, then you can use the draft articles.
Step3: Using the draft Article Id and new file name of the articles in the CSV file, you can use the dataloader to update the Attachment file name of the Article type.
NOTE: Using dataloader you can't update the publish status of the Articles.
