Many individuals download from FamilySearch Family Tree to save them a lot of time doing data entry. With Ancestral Quest this can be done with a few clicks.
Its best to add at the end of a line or start with a deceased ancestor. Once you locate them and you have linked them to FamilySearch Family Tree, keeping them highlighted, you'll click FamilySearch in the AQ menu, scroll and click on "Import Family Lines".
At this point the program already had "Add Ancestors to the end-of-line person" ready to go with the individual I had highlighted.
Notice under "Additional Options" that I can state how many generations to download and to include families and spouses of children. You'll need to check those boxes if you want that to happen and be added to your database/family file.
At this point I can click on "Import" and I will be prompted to make a backup, one should always make a backup before importing anything from anywhere in case something doesn't work properly.
I can also change my selection to any of the other selections, however, you may be asked for their FSPID number so one should write that down if you are doing something different.
Once you've passed by the backup, it will start to import and depending on how many generations it has to download will determine the length of time it takes.
There is a progress bars that lets you know where its at in the download process but once it is complete those individuals will be added to your database/family file. You may to connect them to the family they need to be connected to.
That is it, with a few clicks you can easily update your own database/family file.