Updating indexes in Pincone to reflect an updated source

I have a chatbot hosted on AWS that makes use of PineCone and relies on the Langchain library.
I have many PDFs in an AWS S3 bucket which the vector store is based on.
I see an upsert facility for PineCone but that seems like it’s used to redefine the specifics of an index rather than reflecting that the content that relates to an index has changed.
If a PDF is updated, how can I update the vector store to reflect the new version of the document.
Appreciate any comments / guidance or pointing me to relevant articles.