Oracle Change geometry elements

Note: you can only access the SDO_GEOMETRY inner structure if you use a table alias (in this case 't')

define tablename=Table1
define geocolumn=GeoColumn1
update &tablename. t set &geocolumn. = 
  mdsys.sdo_geometry(
      t.&geocolumn..SDO_GTYPE
    , t.&geocolumn..SDO_SRID
    , mdsys.sdo_POINT_TYPE(t.&geocolumn..SDO_POINT.X, t.&geocolumn..SDO_POINT.Y, NULL)
    , t.&geocolumn..SDO_ELEM_INFO
    , t.&geocolumn..SDO_ORDINATES) ;