If you have a big VCF file with hundreds or even thousands of contacts, doing it manually is almost impossible. I recently used
WholeClear Split vCard Software, and it worked surprisingly well. You just add the VCF file and the tool automatically separates each contact into individual vCard files. It keeps all contact details like name, number, email, and even images intact. The interface is very simple, so even non-technical users can use it without confusion. It supports all vCard versions and works on Windows systems. There’s also a demo version to test before buying. It saved me a lot of time and effort.