It is not necessary to remove any part of the engine box or steps. But it is most definitely a PITA to add oil to the engine.
After struggling for many years, I drilled about a 1.5" hole in the top of the engine compartment that was directly in line with the oil fill. Now to add oil I just put a long funnel through the hole and down into the oil fill. No mess, no fuss. My plan is to get a snap-in plastic plug to fill the hole, but it's a ways down my job list. Or you could drill the hole for a small deck plate. Your choice.
The hardest part of this modification is to accurately locate the position of the hole. My location is not perfect, but it still works ok.
I think I can find a picture in my files if you want it, but I think my description above is probably adequate.