It's not that difficult. Grammar is logical, few exceptions, not many hard sounds to learn for English speakers. I found it easier than Russian for example (took the YKI test for citizenship some years ago).
Greek is also very synthetic, so a little basic vocabulary goes a long way. I like the word for "waterproofing", literally "against-through-rain-making" (αδιαβροχοποίηση, a-dia-brocho-poiesi)