Has anyone changed the water cooler in an IRD unit, its the 2 pipes that go in to the IRD box does anyone know is it a press fit for example does it need to go to a machine shop or can it be tapped in gently

Don't quote me on this but... I think the seal that goes around it is plastic so a tap-fit would probably suffice. I'd not expect the pressure inside the IRD to be too great - it's vented after all - and a press fit would only normally apply to a metal-to-metal fit.