How can I delete an entire line (or group of people) from my database?

You can't mass delete people but there is a way to remove a group of people from your database.

1. Do "File > Export GEDCOM" from the RootsMagic menu.
2. Choose to export selected people. RootsMagic will bring up a list of people in the database.
3. Click the "Select people" button and choose "Everyone in the database"
4. Click the "Clear people" button and choose whatever option you want to clear the people you don't want in your database anymore (ancestors, descendants, etc). You should now have 'X's next to only the people you want to keep.
5. Click OK
6. Make sure to check the boxes to include all the different info (notes, sources, etc).
7. Click "Export" and save the GEDCOM file.
8. Now create a new database ("File > New") and import the GEDCOM into it ("File > Import GEDCOM").
9. You now have a database minus the people you wanted deleted.