Just to let you know, I have received a reply to my email and I'm informed, as I suspected, there are no printed instructions on how to do this.
It's as I said earlier.
You disconnect from the inlet valve (or filter if fitted) and at the bottom of the freezer door (just under the machine behind the plinth) then, it has to be pulled into the fridge cavity.
The new tubing then has to be fed through the old holes into the underside and reconnected.
I still suggest a couple of connectors for an easy fix.
You'll find it's done my most repairers and some suppliers even sell the water bottle with a couple of connectors.
If you copy and paste the following into a new browser window, it will bring up a video showing how to replace the bottle.
Good luck with the repair.
Hope this helps