How to replace/ clean the brushes in the Kenwood Chef- Titanium kmc010

Dear readers,

I have the following problem (since yesterday) with my Kenwood Chef-Titanium kmc010 (3 years old);

When I started the engine, It's spinning around a bit but with shocks.

Sometimes he even does not run (continuous) and I need him cranking up.

The gear operates noticeably, but the engine does not come at the correct speed.

I think I have to clean the carbon-brushes. (there could be some leaked juice in it).

So, I decided to open the machine. (what I've been doing for years with broken machines)

After removal of the drive belt, the motor is still spinning around a bit with same shocks.

I note:

- The electronics (in the Speed Control Module) look fresh and do not stink or smoke.

The motor:

-The Small Pulley does not have a Tension Pin or Screw .. (see picture)

-The back fan also has no Tension Pin or screw ...

-The plastic motor-jacket is completely closed.

-There are 2 mounting screws in the chassis. After removal, everything is still stuck.

So the Pulley has to be removed? But how? Pulling, heating, striking, sawing?

Who can help me with this?

Thanks in advance.