Pull down any scaffolding you see throughout the game to reduce the amount that you need to farm afterwards. It does not need to kill or injure anyone to add progress.
The easiest place to farm the numbers required is in the south-west Wilderness area, at the Excavation Site south-west of the Oasis with the viewpoint. Fast travel to the Oasis, ride your mount to the front gate, pull down the three scaffolds, then run/fight until you can fast travel again and repeat the process.
Notes:
* You must fast-travel, load from a save, or be a large distance from the scaffolds for them to reset.
* Reloading a save after pulling will not add to the count, quick-saving and then reloading sometimes works.
* For the above reasons it's best to fast-travel (which autosaves, and resets the scaffold) if farming.