Open the blend file in Blender 4.2 or newer. Adjust Value in the Shape Keys menu. Changing Value by 1 will offset each mouth by 1mm. Setting Value to 0 will basically reset the duct to its original shape.
Export your modified duct using File → Export → STL (.stl). Make sure Scale is set to 1000 and save the file somewhere you'll find it.
The author remixed this model.
Mouths slightly off centre, which should improve cooling. Still requires the bracket from the original thing.