Your starting point is the Place de l'Ancienne Douane (Koifhus) in the old town, at the little Manneken-Pis statue on the corner with the Rue des Marchands. This is self-guided: no guide meets you. Just open the link on your phone and begin.
The route finishes at the Maison Pfister on the Rue des Marchands, in the heart of the old town, just a few steps from where you started and from the shops, cafes and the Christmas market squares.