Trying to work logistics on train travel. Looks like I would arrive @ the Paris St. Lazare train station. I would then need to transfer to the Paris East Station. Is 1 hour 25 minutes to transfer doable? How is this accomplished? Bus? Subway? I've never been to Paris so.... need some guidance. Thanks in advance.
There are many Metro routes available, all involve one change. Another way is to take the RER E train to Magenta (Gare du Nord) and walk the last few blocks to Gare de l'Est. There is also a Metro connection via the #4 line for just one stop. 1 hour 25 minutes is plenty of time. You'll be able to have lunch at Gare de l'Est.
You can use the route planner: http://www.ratp.fr/itineraires/en/ratp/recherche-avancee
edit-There are several bus routes as well.