Hey man 
I did it like you are showing only i dont have that Generate button …as i dont have Simplpoly. but the thing is I made Static mesh with name_LOD1 not the actual map.
But tinkering more and more i Found out that you Need to make a New Map not a Static mesh to have that _LOD1 information
I would suggest to add to Documentation that … its not the Static mesh file what needs to have that _LOD1 name but a new Map with that static mesh inside in that Map to LOD work …
I hope i will be able to make short Video tutorial as i see that ppl have problem to understand this topic.
thnx for your response