Via public transportation. I know I’d take NJ transit to New York, but where to get off? Penn Station, and then take a subway to Lower Manhattan? Please help!
It would be nice if there was still a World Trade Center… the PATH station there would have been convenient. 
Crap. I was about to tell you to get off in Newark and take the PATH.
In other words, I dunno, but one of the other NY dopers will hopefully be along to tell you.
I suspect that the subway would be involved, and possibly PATH, but I’m not sure. I’d take a look at the NYTransit webpage, whatever that is. (ain’t I useless…)