You can do it from below, you will need to remove the starter motor to get at the sensor, the method for removing the starter is covered in the Haynes :) Just make sure the car is supported safely with axle stands before getting underneath

can the starter motor be removed from underneath or from top? Haynes talks about removing after inlet manifold is out, id like to do it without. I could not see the starter motor from top so hoping I will be able to do it from the bottom.

so I finally got this fix and was driving happily until car started to misfire a lot, only light I got was the EPC light come on.

Not sure what could be wrong now, will be giving the garage a call once again.

Any ideas?