code: function propReplace(obj, prop, value) {
      var o = {};
      for (var p in obj) {
          if (o.hasOwnProperty.call(obj, p)) {
              if (typeof obj[p] == 'object' && !Array.isArray(obj[p])) {
                  propReplace(obj[p], prop, value);
              } else if (p == prop) {
                  obj[p] = value;
              }
          }
      }
  }
docs: helper recursive prop search+replace