Hi Andy. Only read your post late last night so sorry for the delay.
My dissertation on the helibars only showed the left bar switchgear removal.
You don't need to remove the bar end weight, twistgrip or throttle cable housing to get at the switchgear.
The screws are Torx T8. If you look at the one on the front of the left hand switch, which is much more visible and accessible, you will see the size of the head quite clearly.
Now, the only problem on the right side is that the screws are deeply countersunk so you will either need a long-shanked T8 OR, because I don't have one that small (because the long-shanked T handled Torx set from Aldi/Lidl that I invested my savings in only goes down to T10), an Allen key to fit AND because I can't find anything at the moment, let alone a small set of Allen keys, I can't tell you which size.
When you remove the two screws (white bed sheet on floor, towel draped over fairing and tank etc. etc.) the top and bottom halves of the switch housing then come apart exposing the throttle cable wheel and the screw on the top of the bar that holds the throttle assembly from below.
I have photos of these steps but haven't yet got around to replacing BotoFuckem.
If you can confirm that your e-mail address is still @ntlworld.com I will mail what I have to you.
However, when you get the switchgear apart, it is micro-surgery at the best, not a great set of clunky switches like the old originals which you could mend with a hammer and a welding torch.
Good luck.
