You will be able to update your pedigree on the Manage your Connections page of the Share and Compare tool. You can move entries around in your pedigree, by clicking on your relatives name and changing the relationship listed within the drop down menu on the right hand side.
If you have established a sharing connection with another 23andMe member, we will automatically use their profile name within your pedigree. If you would like to update the name of an existing entry that is not linked to a genotyped profile, you will have to delete that entry and recreate a new one. You will be able to remove entries by clicking on "Remove Connection" at the bottom of the panel on the right hand side of the screen.