It's fairly easy and there are a lot of forums around with knowledgeable people.
My main issue was ensuring wire gauges were correct. One's intuition about dealing with house wiring @15A changes when you're dealing with 50A circuits. Also you need to pay attention to things like equal cable lengths between battery banks so you don't overcharge one battery in a series.
However, I'm dealing with an off-grid cabin so I don't need to deal with any grid-tie circuitry, which would make it much more difficult and I'd definitely get an electrician for that.
Modern off-road/off-grid inverter chargers make wiring to the network pretty easy. I'd still recommend an electrician, but most they'd likely need to do is wire the grid into the inverter-charger input, and your cabin to the output, and check whatever protection (like RCDs) your cabin has is sufficient/up-to-date.
Very cool. Thanks for the tips!