I have a landscape material like in this video v=MzAAepWKMr4I want to be able to have a beach only at this one area at the ://prntscr/6gwfm3
How would i be able to do this without getting rid of my old material from the video above
Bump still wondering if anyone knows how to do this
I havent watched the video, but you just have to add a landscape layer node (https://docs.unrealengine/latest/INT/Engine/Landscape/QuickStart/5/index.html) into your material. 
The video shows automatic texture placement based on slope angles. The beach however will need to be hand painted.
I personally find you get much better results using selectors and outputting textures layers from world machine. Much better results, which can be edited later by hand to make areas unique and interesting.