How to update Android LiveData Factory

Question

I am using Room database layer with LiveData and PagedList to render a ReceycleView List of chat messages in my app.

This is how my setup looks like:

    DataSource.Factory<Integer, Message> factory = ChatDb.getMessages(conversation);
    PagedList.Config config = new PagedList.Config.Builder()
            .setPageSize(50)
            .build();
    LiveData<PagedList<Message>> liveData = new LivePagedListBuilder<>(factory, config)
            .build();
    liveData.observe(this, adapter::submitList);

When the user moves to a new conversation, I need to re-query Room with a new conversation object.

What would be the proper way to clean up the old factory and the liveData, and is there a way to reuse any of those?