How do you get from Gare Saint-Lazare to the Eiffel tower?

Answer 1

You can walk - the two stations are at opposite sides of the river, but not very far apart. More practically (if you have luggage) you can go by bus - number 61 does the trip in 5 minutes. As you leave the station, you'll find local plans posted to show you where the bus stops (arrets d'autobus) are. You can go by metro - line 5 to Bastille and then Line 1. This will take much longer. Of course, you could take a taxi, but that's cheating.

Answer 2

Not simple, this. You have to walk down to Metro saint-Augustin and travel on line 9, direction Pont de Sèvre, to Trocadéro. You could then take line 6, direction Nation, to Bir-Hakeim, which is marginally nearer the Tower, but my advice is to surface at Trocadéro and walk through the central space of the Palais de Chaillot, where you get the classic spectacular view of the Tower, and down the hill and across the Pont d'Iéna.

Lots of walking, but that's the way to see Paris.