Rebuilding Märklin 36611, CargoNet 119 002,  to sound with the Märklin 60949 conversion set
This procedure works also for other Märklin models based on the same locomotive chassis.

Updated 14.06.2013

Märklin 36611, NSB CargoNet 119 002

Preparations for the conversion:
First of all, remove the old decoder by unsoldering the red and the two brown wires from the decoder.  Carefully pull the flat leads to the lamps out from their connectors.  After removing the four screws securing the old decoder, carefully lift it out, with the motor.  Pay attention to the propeller shafts at each end of the motor.
Make sure that the locomotive works perfect mechanically, like the gears, wheels and shafts.  Clean it well before installing the new parts.  Carefully oil or grease the rotating parts - if required.

Märklin 36611 inside before conversion:

The photo also shows the parts from the 60949 conversion set, with very good instructions in six languages; three booklets with two languages each.

The original decoder and motor:

The motor sits under the decoder.  It must be unsoldered from the original decoder.  A sticky pad is glued to the motor and to the decoder.  I did not straighten the soldering lugs on the motor.  Carefully lift the decoder from the motor in the flywheel end and slide it out under the bent soldering lugs.  I used a "solder sucker" to remove all the solder from the solder pads and lugs.

The new decoder and the motor:
Slide the decoder adapter plate in under the soldering lugs an press it firmly against the sticky pad on the motor.  Solder the lugs to the soldering pads on the adapter plate.

The new decoder
Insert the propeller shaft into the universal joints at each and of the motor and carefully "drop" the decoder/motor unit to it's position, while passing the white speaker wires through the pipe/hole in the locomotive chassis.  I had to "puncture" the hole through the chassis floor.   Do not tighten the four screws until all the screws are installed.  Solder the three wires into position.
Leave the four direction jumpers as they are.

Carefully insert the plastic leads to the lamps into their connectors.  Carefully install the new decoder to the adapter plate.

It is a premade space for the 8 Ohm speaker under the chassis.  Solder the two white wires to the speaker's solder pads and secure the speaker with the black plastic bar.  The bar must be pressed rather hard into position.

The Märklin 36611 inside after the conversion:
The old decoder on the closed installation instruction.

The 36119 NSB CE119  function table:
36611 NSB CE 119 002
mfx sound Light Sound
Horn 1 Acc/
Sound Horn 2 Sound
funct. dir. front rear coupl. uncoup
f0 forward 3                                
reverse   3
f1 both     on                            
f2 both       on                          
f3 both         on                        
f4m both            delay off                      
f5m both             on                    
f6m both               on                  
f7m both                 on                
f8m both                   on              
f9 both                     off            
f10m both                       on          
f11m both                         on        
f12m both                           on      
f13 both                             on    
f14 both                           on  
f15m both                                 on
Stop forward                                  
Drive forward                                  
   f??m = momentary function

Märklin Central Station 1 screenshot:

Future improvements:
As the decoder adapter plate has four outputs for physical functions, AUX1 to AUX4, maybe I will install cabin lights front and rear, using small LEDs.
I will also look for other head light units, maybe with rear red light and/or high beam lights, if this exists in another locomotive.
I will probably replace the white speaker wires with black ones, as the white wires are quite visible under the locomotive, from a low viewing angle.