Perfect timing I suppose
I have one in my shop as we speak
once you remove the nut ( the model I have is normal thread counter clock to UNSCREW)
remove also the big metal disk around it hold by the 4 screws in the top
that you will have a better clear view
the rest should be easy
here are 2 pics

Stefano,

How did you get the top burr thread housing off? Did you have to use the vanes to hold the nut in place? When I tried to remove mine the vanes started to bend.

I think that is my biggest challenge now. Even when I remove the screws, the housing would not budge.

Thanks!

-Bill