Copying the characters for a sequel

Hi, I have finished my book but at 260,000 words I am splitting it into two books as it was a dual timeline anyway.

So now I have to start a new project and copy half the chapters over, but half of the characters are not needed in the sequel.

Can I copy the character data base or somehow copy them individually into a new database?

I have managed to open the character database in the second project but if I delete a character it deletes it from the original project too, which I obviously don’t want as there will be further projects with those characters in them.

I would prefer to copy the whole thing and delete the characters I don’t need, rather than having to copy them individually to a new database. But if I have to I have to.

Or do I just have to start a totally new database and re write it all?

Thanks in advance.
Christine