Cut the drive shaft off with a angle grinder close to the wheel leaving the spline still in the wheel bearing but fully removed it from the diff... took the prop shaft off and lifted the motor up again. Span both front wheels and it clunked really bad even making the full engine wobble. Keeps getting caught on something inside the ird box. While looking at that found a front drive shaft that was a little wobbley with a split boot so ordered a new shaft for the front too...
My only issue now is swapping out the IRD unit as I've never done one before.
Sounds like my situation.
The gearing in the IRD to the rear pinion wore out (not sure over how long, but I inadvertently drove quite a distance on a tyre that had deflated some). Made a right banging noise when it 'went'.
Removing the props and driving the car, there was a 'ticking' noise coming from the IRD - so it wasn't safe to leave it like that cos the pinion gearing was so bad it was going to jam or summat if I tried to use it.
It was fairly shortly after I had decided to "never use" garages again and do all my own maintenance and it was quite a daunting prospect. But I did it. I got the IRD off, sourced a bearing replacement kit, split the IRD and refitted IRD.
However, I gave the bits to a gearbox sghop for them to push/pull bearings etc. That knowledge I didn't have. It was the right call I think because the kit was missing some seals evidently (and possibly shims?) and they knew where to go to to get the fiddly bits.
You sound like you are much more capable than I was. So removing the IRD should not be a problem and fitting the bits probably.
I got the gearbox shop to remove the crown gear from the pinion. So although I put everything back together as it was, including original VCU, it was only 2WD. That was 10 years ago and the car has given boringly reliable service since.
Over here, if a car is 'modified' it needs to be certified. So removing the props would have needed that process. I think you may have similar problems in the UK failing MOTs is parts are removed. Removing the gear in the IRD 'masks' the 2WD conversion from WOF (MOT) testers so I haven't had any problems. You'll have to put replacement driveshafts in to create the same.