Seperating fsnily tree

You need a GEDCOM file, ab into which you decant the half of the family that you want to move. Then you start a new tree with the half that you removed, loaded straight into it. After that you delete them from the original tree (don't do it too soon, until you know that they have transferred OK!).

When you start to make the GEDCOM file, it asks who you want in it, and you can probably add your father and all his ancestors, or whoever. I have not used ancestry, so I don't know how they do GEDCOMS so I don't know the details. There will be something in the help file.

A GEDCOM file is a database, which has all the info in a grid form. Family tree apps and progs can use it to put the info into their display.