Hi,
I have no idea how to remove the front grille of Octavia but to solve out your problem I found out one video which is showing to replace the new front grille with old or damage one. May this video helps you. Have a look
The company that carried out the service should have reset the service light. I would take it back to them to change.
However I will list below how to do it although this will change your servicing from variable to fixed so it's always best to take it back to the company that carried out the service.
1. Ignition off - Press & hold trip reset button.
2. Turn ignition on - wait for 10 seconds.
3. Release trip reset button.
4. Turn ignition off.
S.w off , press button and hold , S.W ignition ON, turn to anti clock wise and hold till (--------) comes , S.W off and ON a gain ,do same step if (insp.)
remove fuel hoses out , there is 6 bolt a round the cove remove out the cove , keep the plastic ring new ,replace the fuel filter ,keep the location of hose you remove , re fill container with diesel , then fix bolts
check heater plugs ,it will take around 20 second if heater plug is
not working one or more it will take 10 second . you can S.W ON and off many time so. the engine warm.then try to start
make sure oil and filter are clean, coolant is topped up. Check there is no water in the oil. check air filter is clean. check fuel filter is clean. Put some injector cleanrt in the fuel and go for a fat drive
If you find water in the oil and there is overheating have it checked.