EASY PEASY swap
two maybe three issues
One the plastic frame that retains the cables inside the down tube it was a RPITA to get the cables back under that frame AND slide it into the three grooved retaining studs
Eventually I had to leave out two cables connect the frame to the bike {it slides on with keyhole slots in the frame} and use some car interior trim plastic tools to lift the legs of the frame and slide the cables under the frame
I removed all six DU retaining bolts and lifted the DU about an inch and the cable went in and out eaisly. However it would not go back in easily. The gearchange cable slipped in between the DU and the bike frame, so until I identified that issue and held the cable well away from the edge of the bike frame the back of the DU would not drop down and line up properly. Once the cable was out of the way it was easier to slide the DU down between the frame {it is a very tight fit and with the DU out the gap had reduced}
All in all an easy and very nice upgrade.
One other issue, Fitting the KIOX display. I thought I would need to change the stem fitting for a longer and shallower angled one, but after lots of thinking and mucking about I decided to drop the existing stem fitting down a bit to give clearance for the KIOX mounting bracket. As the stem fitting is a short 30 degree one it fouled the KIOX mounting bracket if it was fitted 'normally, This required me to redistibute the three existing stem washers two to the bottom and one to the top to make the display mounting bracket fit, this dropped stem fitting lower by 10mm and that allowed the display to fit without it or its cables fouling on the fatter boss of the stem, that the two top handle bar fixing bolts fit into.