Jul 19, 2015 - 6:07 PM
Hi Amit,
Thanks for the additional information. You can best go to the staffed ticket counter of the Luzern rail station and ask about the options. I'm not sure if upgrading to 1st class is possible without cancelling the 2nd class pass, but they should be able to tell you.
Let us know the outcome if you will. Thank you, enjoy your traveling!