Take a look at this section in the UDK forum: https://forums.epicgames/forums/369-Community-Content-Tools-and-Tutorials? (especially the first thread)
You can also find free assets on turbosquid -> just set the price filter to 0 
Take a look at this section in the UDK forum: https://forums.epicgames/forums/369-Community-Content-Tools-and-Tutorials? (especially the first thread)
You can also find free assets on turbosquid -> just set the price filter to 0