Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Slide the spark generator out of its
catches and place in a safe location
Disconnect the electrode leads from the electrodes
Remove the two nuts from the electrodes and withdraw the electrode assembly

Observation:

Check the electrodes are not warped or damaged.
Check the ceramics are not damaged or cracked.
Check the ignition electrodes spark gap.
Spark gap should be approx 4.5mm.
The ignition probes should also angle slightly downwards
as shown in the picture.
Note:
Per manufacturer's instructions, upon reassembly a replacement gasket (part number J04357) for the electrode assembly is required.