Spark plug replacement

[LE62NDE]

I think I know the answer to this, but with my first indy service coming up, I thought I'd check as I need to tell them what needs doing. I'll do the pollen and air filters, so its engine and gearbox oil, plus the oil filter. But spark plugs look to be up for replacement at 6 years or 36000 miles; with my car on 4 years/37000 miles, I'm guessing they need changing. Is it a straightforward task to replace them, once the undertray is off?

[matt5964]

We went for the NGK ruthenium

https://ngksparkplugs.com/en/products/ignition-par...

All straight forward, you won’t need the undertray off… but the intercooler does need moving to get to one of the pluf]gs, so takes a bit of time to complete

[PHusername]

I saw an interesting video of a guy working on an AMG V8 (Legit Street Cars out of USA). Engine failure partly due to incorrect clocking of spark plugs. That's a new one to me. There was a TSB for it because some aftermarket spark plugs could end up facing the "wrong way" when torqued correctly, so the spark doesn't ignite the fuel spray as intended.
Whilst I doubt our DD engines are that sensitive to the where the shadow of the ground or side electrode is, it has me wondering.

I have NGK Laser Iridium ones waiting to go in. Part number DILKAR8R9HS