Use the same mod. as the 857/897 except you will place a jumper (solder) on pad 106. On the 857&897 this is left in. On the 857D & 897D it is removed to give you 60 meters.
It needs to be replaced to give you HF freq's. So in short, 1003, 1002, 1001, is removed,1006 jumped 1005, 1004, removed and 1009, 1008, 1007, jumped. You will loose the auto offset and the pre programed 60 meters.
Not a big deal turn menue 2 and 3 to off. this will leave offset in the same mode until you manualy change it.