We’ll choose a different method, the simplest, depending on the side concerned. Note: on the photos, end 1 is on the right.
Here is first an overview of the changes.
The 1 kΩ resistor is unsoldered, offset (2a: dashed, old location) and then re-soldered with a free end, on which a wire, preferably green, is soldered. The other end of the wire is soldered to the side of the NEM connector pin 3 (2b). To facilitate the operations and if you are as skilful as me, I advise you to first unsolder the light green wire, in order to clear the operative field, and to put it back only in the end…
Here, it is best to cut the showed track (3a). The wire, preferably purple, is soldered to the end of the resistor whose track has just been cut (3b). This wire can be directly the decoder’s, but I prefer to insert a plug made with two tulip pins, in order to be able to disconnect the decoder without difficulty.