I’m thnking of going from a triple to a double chainset. Other than a new chainset and shifter, is there anything else invovled?

Check frame clearance (chain stay) for the double you are considering – should be Ok.
You missed out the front mech

You may need to shorten the chain as well. Depends on the size of the new big ring compared to the old.

Whenever I’ve done this on a mtb I’ve kept the shifter and derailleur, can’t see why you can’t do the same on a road bike! 🙂

If you tighten the end adjustment screws on the derailleur then it’ll resist going into the third, now redundant, chainring

Cheers to all. I may just take the plunge and overhaul the drivetrain.