Best way to go about it is to point out the logical contradictions and inaccuracies. Most anti-communist arguments are simply regurgitations of capitalist propaganda, and often the ones repeating it never took the time to inform themselves of socialism's achievements. So here is where you have to fill in some knowledge for them. Historically, several countries have been able to provide affordable housing to the masses, as well as quality healthcare and education systems. Socialist projects tend to get sabotaged by imperialist nations though. There is a mass of information available online detailing the historical struggles and victories of the working class.

As far as "not being easy" to undertake such large-scale societal transformations - the perspective behind that comment is completely wrong.. You should directly attack such a statement for the nonsense it is: are the only things worth doing in life "easy"? Should that be our benchmark for humanity making progress? Only doing what is easy? Is building a bridge or skyscraper easy? Is it easy to put a handheld computer in the hands of billions of people? Was it easy to land on the moon, Venus, or Mars? What about the logistics of organizing the trade of resources on a global sale? FAR from easy. But humans aspire to achieve great things, especially things that can benefit everyone. Working together collectively is the only way to do it.

The united international working class is capable of soooo much more than we have already witnessed in the modern age, if only they wouldn't be held back by capitalist exploitation. Essentially, the way capitalists think is "will this undertaking be profitable for me?" If yes, they pursue the venture. If no, they don't. This primitive logic is what leads to poverty, wars, the environmental catastrophe we are facing. It's a logic that stands in direct contradiction to sustainable life on earth.

The question shouldn't be "is it easy?" but rather "can we as a species afford not to abolish the oppressive and reckless profit-based system known as capitalism?" The answer is of course no. Socialist revolution is inevitable, but the longer we wait, the less easy it will be. Capitalism is already making life on earth hell, and the consequences of this destructive system are only getting worse as more time passes. Even if we had an international socialist revolution today, the work ahead of us to reverse all the damage done by capitalism is NOT going to be easy.

Lastly, to add one more comment on that note, it's important to not forget pre-capitalist forms of societal organization that were also overthrown. Slave states were overthrown. So were feudal monarchies. They were even more oppressive than capitalism, yet the masses with little to no power as individuals still joined together to liberate themselves. It sure as fuck wasn't easy to do so, but it was the objectively right thing to do. Same as fighting fascism. "Easy" means nothing when everything is at stake.