Originally Posted by
JBord
Hbf is a little easier. In fact, I'd suggest going to Hbf, which connects with U4, and then take the U4 straight to Stephansplatz. You get to see St. Stephens as you exit, and it's a nice walk just a couple blocks to Hofburg.
just to avoid confusion, this is referring to the U1 (red line, as deniah mentions) not the U4 (green line)