Turn the grinder over again, and carefully lift up the capacitor as shown with a any suitable tool to hand: a small flat bladed screw driver is fine.

In addition to the two capacitor leads, there are what I take to be red and blue stator leads. As normal on such tools, it is a universal motor with 2 simple stator windings and a more complex rotor with brushes. The brushes are at the top and bottom, and can be inspected at this point.

You might need to change or service the brushes at this point, but that is not covered here.

Remove the red and blue stator wires from the switch next to the capcitor leads. Use long nose pliers to pull off the crimp connectors: this needs a bit of force, so be careful and pull directly along the terminal axes. The picture shows the blue wire disconnected.

Examine the switch and note how the black rod engages with the push button.

Notice that the switch has what seems to be a copper heatsink on the side nearest the blue lead.

The switch is now held only by the two grey plastic clips.

Insert suitable spacers between the body of the switch and the clips. I cut a wooden cocktail stick in half, and inserted the sharp ends behind the clips and tapped the pieces until the clips were just clear of the switch.