If it is the front one above the cat I think it is easier to get to it by reaching over the engine. I haven't had to get to it, but I know I have seen it while looking back there.
Based on what I remember you need to get the plug disconnected which is located on the back of the motor behind the intake box. Getting to the sensor is the part I dont remember.
The EPC was from ebay UK but is probably avaiable over there...
The Service Manual was from the states on a CD, but messaged the guy to see if he could email the link for the pdf & save me postage costs & just buy the data..... so thats what i did.... ;-)