Actually with the ESS kit, most of the airbox, etc has already been removed and replaced with the new ESS manifold which doesn't cover the spark plugs.
The left front, just take off the spark plug cover and you see them all. On the right, you may have to unbolt the supercharger or take off the plastic intake manifold behind it to get to the spark plug cover. I haven't put that one back on yet after changing the plugs. Think I might "trim" the right spark plug cover to fit so I don't have to take the supercharger off to get in there.
Cost me $32 to get a spare right cover to cut-up, just haven't done it yet
2011 e92 M3 Monte Carlo Blue ESS 535
2010 Honda FIT
2006 SLK 55 AMG