We bought our 9:39am train tickets from Prague to Budapest yesterday at the train station. The price was steep: about 90 euro for 1st class as opposed to 36 euro which was available online 3 days before. So definitely plan ahead!
However now we realized that there's a place we really like to visit before leaving today. So my question is that since we bought the full-fare (?) ticket, is it possible to change the train ticket to a later time in the day? If so do I need to go to train station again to do this? We bought the tickets at the CD travel center but they don't open until 9am today.