Sometimes there is an aspect of an awesome model that doesn't fit your specific needs. Therefore, this video covers editing a Unity Asset from the Asset Store using ProBuilder. I really like all the ProCore tools, so I'm showing how to use one feature of Probuilder here.
ProCore tools
https://www.assetstore.unity3d.com/#!...
Extreme Vehicle Asset
https://www.assetstore.unity3d.com/en...
http://vertigo-games.com/