As @Chris.ac mentioned, a photo would have been handy when I had a go at getting access to my blocked drains.
So, here you go and my story...
It was hell trying to get the left nut undone on my 2008 Alphard, it had locking glue on the thread and I suspect never removed before. I had already got the nut off here before I thought to take some photos.
However, the right nut was much easier - just a single turn was required.. and POP!
So, instead of this...
The right hand side is now like this..
And discovered it was unhelpfully not an easy replacement...
Frustrated, I retreated inside with the sunroof to investigate fixes to my screw-up...
As everybody knows, a story like this is always improved by adding the phrase "and then it rained..."
So it did exactly that. /sigh
Well, at least the drains are now unblocked.
EDIT: Any tips you may have on where to buy a replacement part would be greatly appreciated!