Well, that's the hard part done. Bloody bar inserts out. Might be alright when new but takes a bit of huffing and puffing at 12 years old! Properly on with the job tomorrow. And I've new grips to go with them. Really nicely machined and will hopefully see me put another forty thousand miles on her.
So....first issue. Top yoke nut. A very odd 37.5 mm or some sort of imperial thing! Who knows. I wonder if there's a special tool from triumph? Thankfully, a pal had just the ticket...As others have suggested...a wrap of tape on the anodised top yoke nut helps avoid ruining the finish.
I've got the helibars instructions in electronic form if anyone ever needs them. They suggest start with the RHS clipon. I doubt it makes any difference. First remove top yoke nut and slacken pinch bolts, then lift off top yoke. It lies just fine under the screen. Then slacken off the clipon pinch bolts, undo the controls and replace the bars. The only real issues I found are the helibars come with a different brake reservoir mount which is a bit fiddly and it's tight but doable to insert the small bolts from underneath which locate the helibars to the top yoke.
The only thing left to do is reattach the factory bar ends to the helibars (new bolts needed as mine are slightly stripped out in the head) and clean the thing. Took me two hours and I'm very slow with this sort of thing. Torque wrench essential to avoid damaging the fork tubes/clipons etc. Below are some before and after shots. It doesn't look that much different but changes your riding position quite a bit. Pleased I've done this.
I can confirm that these are a great mod - have them myself. Gets rid of the ridiculous wrist-stress-inducing down and back sweep of the OEM clip-ons. You also end up with a wider grip so its easier to muscle the bike around on country lanes.