Jonny's website (Classic Retrofit) includes quite detailed instructions for the later impact bumper (horizontal) replacements, but nothing specific for the vertical ones yet.
Anyway this is how it went and a few tips for others giving it a go.
I started with this

and with the covers off

As Jonny's says in his write-up, take lots of photos and make notes of all the connections - especially those on the back of the fuseboxes, and any 'jumpers' installed to connect fuses together. Most of these cars have had some mods, or options that are not shown in the standard wiring diagrams (power windows and a rear wiper in my case). Battery isolated (and the nearby +ve terminal covered) - a must!
I then removed the mounting screws and removed the wires one by one from the RH side and installed them straight into the new array starting at the bottom. I found there was enough give in the wires to do this easily. Once at the top you have something like this.


Now it got tricky. I found it impossible to progress without removing all the LH wires from both the old fuseboxes, and getting them out of the way. This is where the photos and notes became essential. Still cocked it up ....

Looks right, but it turns out I got some of the indicator wiring wrong, and this gave some interesting outcomes when I tested the system (both front lights flashing on LH, only RH rear on RH). Also diagnosis was much confused by what turned out to be an existing dud bulb in the front RH sidelight. So a tip would be check everything works as it should before you start! Anyway tracked the problem down by systematically taking all four side and flasher fuses out and seeing which 'tell-tale' lit up when that circuit was switched on. (Good tip from Mr. Hart by phone)
Anyway you must remember the isolating sheet that goes down the back

It is important that the central fastening screw has a good earth for the relays, and in these models the screw is secured to the body by a spire nut - not the best thing to get a good connection.
So I decided to fashion a earth cable from the screw to the main battery earth nearby. You can see it (brown wire) in the photo below.

Fit the new cover and all done. Overall about 2hours, mainly the faffing relating to my wiring cock-up. The 3-way rear fuse box is a doddle - took about 10 min. Spent a bit of time after this tidying up the wiring as I like it neat and tidy.

Hard to say if the headlights were brighter as it was a sunny day, but the indicators certainly flash 'crisper'.
Happy customer.

