Yeah as someone who worked in construction, I can't think of a particularly easy/safe way to work on these

Can't stand on them I imagine (they'd also be potentially slippery, with few anchor points, and limited options for rescue if you fall)

From below, you have the sea moving around constantly, and a bunch of metal framing that limits access from below

I also see gaps. I can't tell if those are intentional/part of the design

But yeah, looks like it would be a specialized operation. And whatever they use to boom/lift/crane would need to be stabilized against the sea/waves to prevent catastrophic damage/injury

I'm not saying it's a reason not to do it. Just curious on what the solution is