Sid,
Done mine today, book says every 2 years or 25000 miles, yes it is a bit of a faff. Next time I will, remove the black protective bit from around the filter, then pull off all the pipes (noting where they go back, then lift the filter and housing out. Pour any diesel in the old filter into the new filter, put back all the pipes making sure they all"click" home but leave the outlet of the priming bulb. Pump the priming bulb until diesel comes out then put it onto the filter.Close up the filter housing with the pinch bolt, replace the black protective cover. Pump the bulb till it goes hard, then start the engine and check for leaks.
The water drain location is a joke, it's supposed to be drained of water at every service, you need to remove the black cover to have any chance of doing that so contrary to what the service book says I reckon it rarely/never gets done.
Hope this helps