I need a tutorial that actually shows you how to build a big landscape and break it into tiles. and export it as tiled heightmaps. I watched the one linked in the other thread but it doesnt show you how to do it it just shows him doing it with no explanation and some stuff is already done.
Probably this tutorial will help you: https://wiki.unrealengine/World_Machine_to_UE4_using_World_Composition#Tiled_Build_Setup 
Set your tiled build settings under World Parameters, then click the tiled build button right next to the “build current device” button. It exports the tiles once it finishes the build.