No ignition spark on CDA SC309SS

I have a CDA SC309SS gas oven that doesn't spark when the knob is pressed. Neither the grill or the oven spark so I assume the ignition unit is the most likely problem as that's the thing both circuits have in common.

https://www.espares.co.uk/product/es1597...

However, I have no idea how to get to the internals to check the part number or actually replace it. Does anyone know how to get into the insides of this particular oven?