his details on getting the guy to fall helped me. shifting the angle, use the dlr hook and distance leg to bump them up enough to shove his ankle while pulling the belt down. it did cause me to loose control of his leg in my dlr but was still under him enough to take the mount like in the ary vids... but this was vs blues... good luck with the browns and blacks. let us know if you get it down.
Subd for later viewing 
Samuel Braga along with Miyao and mendes brothers make a joint video. With the speci bonus video being Ary an then we will know all there is to know