All good now and working.

If you take the L/H front wheel off you can get like if sight to the knurled connector which then allows you with the aid of a long flat blade screwdriver to gently tap the connector to get it moving. Once started it's then usually possible to undo with your hand. It's just getting it started that's awkward.

Having an arm with two wrist joints would help too. 

On a remote shifter, there are two short links on the upper side of the diff housing (called gear change knuckles, male and female). Each one fits onto a splined shaft with a small retaining bolt needing a 7/16" wrench to tighten it. The bolts pass through notches in the side of the splined shafts - loosely, so it is easy to miss-align the links on the shafts by a spline or two either way. If they are not centred correctly, it makes the throws of the gearshift lever really strange, for example 1st may be a long throw curving to the left and 2nd really short.

Of course you wouldn't find this out until the lump, complete with remote shift housing is installed in the car and you've put the shift lever back in. So the challenge becomes lying on your back under the car in a position that allows (I use the term generously) you to maneuver  your hand up over the shift housing with a wrench, undo the bolt, lift the link off the splines and move it hopefully one spline at a time. Then assembly is the reverse of disassembly. Once you extricate your arm and then your body, you can get in the car and test the results. Repeat until you go beyond the optimum solution and retry until "satisfied".

Of course there are TWO links on TWO splines shafts and you can't see either one of them. 

Speedo cable is a piece of cake by comparison. 

I was just thinking today while trying the get my speedo cable off the motor that this would be a great job in Hell to perform daily throughout eternity. Going to try the smallest vise grips I can find to lock onto the knurreled end on the cable to loosen it up.