This is a ticket for a train in Italy. You could have told us that at the beginning, so we would have been able to give better answers.
Changing names is not possible on train tickets. This to avoid people reselling tickets. So you must cancel the ticket and book a new one. Because you choose not to create an account with SBB this involves extra manual work, and you do pay for that.
Now this ticket is for an Italian service, not a Swiss one. In Italy long distance trains come with a seat reservation. You bought a BASE ticket, which is flexible. So you can take another service then the one you booked, but must change your booking. That is the “unlimited booking changes” the ticket mentions.
In my experience the Italian train conductor on the EC is not interested in your name, as long as you sit in the seat your reserved. Is the name on the ticket very different from the one in you passport?
And a last note: Be aware that your ticket is in fact for a bus, not a train…