You can access the pump's impeller from inside the chamber. Remove the filters and right at the bottom of the sump at the very lowest point you may find a single Torx screw - if you remove it you can lift the cover from the pump's impeller - with any luck there will be food debris trapped underneath the blades - remove it with tweezers.
The pump impeller should move freely but with a bit of magnetic resistance.
I've never changed a pump but if I had to I would get to it from below - tipping the machine at an angle.
Good luck...
Peccavi, July 2009
