As you'll see in this post, it is quite easy to convert a Euro 4000 from SudExpress into a DCC engine. For a starter, I was lucky to see on SudExpress website that they provide a ESU sound project:
Here are the links:
Ok, let's follow step-by-step ...
Unboxing
Opening
As mentioned in the manual, there are no screws. Just pull gently on the sides and the chassis will come down fairly easily. The only thing to pay attention is that there are 2 tiny connectors for the head lights that need to be disconnect to fully separate the body from the chassis.
Installing
A small bag is provided in the box with the components required for the speaker.
Putting the 2 tiny screws for the speaker chassis was a bit tricky. I had to unscrew the main PCB a bit to be able to correctly position the speaker chassis with the various holes for screws.
Configuring
Obviously, the DCC address should be 4006:
Testing
A quick video to test everything: