UK Car Repair: vauxhall repairs, oil pressure switch, vauxhall omega

Question
i have a vauxhall omega elite 2.5cc v6 i have just changed the oil pressure switch and the oil light is still on and the pressure is still low what else could the problem be and how difficult is the repair

Answer
Well if both the light is on and the gauge reads low, it may be a real problem.  To be sure you need to connect a pressure gauge up the the engine where the switch or gauge fit, start it and see what the actual pressure is.  If it really is low you have a number of options starting with cleaning the pressure releif valve near the oil filter. Is the engine noisy?  let me know.