So, I'm into it....
In practice, things are somewhat different with RHD from the processes they tell you about in the book (TP 311127/1) or in Robert DIY's video, both of which cover LHD cars.
For one thing, in a RHD car there's no knee bolster on either the driver's or passenger's side.
For another, there was no way to extract this RH (driver's) side air vent tube from behind the dash without first removing the dashboard. Ordinarily, it sits above and behind the instrument cluster. It needs to come out before the blend door box can be removed.
For yet another, it's highly recommended that if you have power seats, you move them into a position whereby you can access the 4 bolts which attach them to the floor before you start disconnecting any SRS components. You don't want to power the car up to move the seats while those bits are disconnected.... That preparatory act then saves you the hassle of dragging out a car battery to power up just the seats (via their disconnected seat motor harness) to move them into the correct place.
Why do you need to unbolt the seats.... well, you need to remove the carpet for two reasons: One is because leaking heater cores dump the coolant into the front foot wells, and saturate the carpet. The other is how you need to loosen the rear seat heater ducting in order to remove the floor manifold - seen below as [21]. The two instances of [26] appear to be located under the carpet.
As you warned me @JamieG, 2 of the 5 the plastic f**karse clips (p/n 1348040, which hold the dash to the firewall) broke in the process of disconnecting the dashboard. Somebody has removed this dashboard before, and wasn't really gentle about removing it.
So an order has been placed with GCP for new ones; they're only 20 SEK each, along with a few other plastic bits and pieces.
If anybody plans on doing this job with their 760/960, I strongly recommend ordering a set of 5 new f**karse clips before you begin. The youngest cars to use them have been baking out of sight for at least 25 Australian summers now, which does not bide well for plastic used in tension.
A new thread detailing the excruciating process of RHD 960/ x90 dash removal and heater core replacement is forthcoming; it's not covered well enough by the green books and the process is very different from 740/780/940.