Creating New Help File from Existing Help File

Good morning! I feel like I've asked this question before, but for the life of me I cannot find the answer. Anyway, I have one large Help file I use for our software. We are currently working on a new software version, so I would like to start a brand new Help file for this new version but I want the topics in my current file to be used in the new file. Does this make sense? Can I copy the contents from one file to another or do I need to import. Our software runs a chm file of Help. The help topics are created in HTML. First I generate in WebHelp and then generate WebHelp to CHM Converter. Running to a meeting but appreciate any comments. Thank you!