Finally got around to fitting the new water pump and hoses. Not terribly difficult, quite straight forward. Not sure why the service manual doesn’t recommend draining the oil. I did anyway. After taking a close look, the hole for the pump may be high enough to prevent any oil from leaking out.
The one part I couldn’t get to work was the coolant bleed screw, I was able to see a little drip when I flushed the system with distilled water but not when I put the coolant in. I was able to get the 3.2 litres in as specified in the service manual so I’ll just keep an eye on the reservoir.