This thread will probably help you: https://forums.unrealengine/showthread.php?297-Curious-if-I-can-open-a-UDK-project-in-UNREAL-4&highlight=Porting 
Basically you just have to export your meshes, textures, sounds -> then import them into the UE4
You can easily recreate the material in the UE4 -> use the UDK materials that you have created as a reference
BSP brushes can be converted to a static mesh -> then you can also export them
the programming and kismet stuff has to be redone!