Bulk resize prefabs in purchased asset package

I recently purchased a city asset package. The new city asset's prefabs are 2x as large as the rest of my assets but are also scaled at 1, 1, 1. I've been manually going into each prefab and scaling them to 0.5, 0.5, 0.5. This workflow wouldn't be that big of an issue if there were only a few prefabs to scale. However, this package has hundreds of prefabs. There has to be an easier way to do this. I considered writing an editor script but I'm not sure if it would actually edit the prefab. Any ideas?

I suppose I could drag all the prefabs into a scene, select them all then adjust the scale and position then apply the changes back to the prefab. It would be a lot quicker if I could do it via script.

Currently working in Unity 2018.4.8f1