Afraid to uninstall safari extension

Had 1P3 with safari extension. Noticed that one computer seemed to stop synching any changes from safari. Safari extension (3.9.20) giving the "cannot communicate with helper" error. Attempted to open 1P3 app on that computer and received error that it could not be opened "because it may be damaged or incomplete." Proceeded to install 1P4 on machine and received helpful notice about removing old 1P3 extensions and instructions to do so. However, the very first instruction is to ensure that the extensions have synched to the main app before you uninstall the extension, which of course they haven't (see first couple sentences of this post). So, I really need to get the updates from the Safari extension (v3) synched somehow before I delete it. Is there any way to do this?