ADF5610 - EXT REF input toward IC Xref pin on EVB

Hi,

i'm trying to enter with 80MHz Good reference yet the EVB document lack some importent description of how to change the EVB to work with External REF, there is no any commant of what to do with , R51, R47, R33, C79, C85, its very basic and no description regarding these parts assembly is very confusing, i did what i think its right yet its very strange such a lack in the official description regarding this parts.