Beginner Question: How can I alter the looks of my Station Schedule?

Hi!

This is my first post on this site, so I hope this is the right place to ask questions. Basically I have a drupal 6 site and added the station module. I now want to alter the looks of the station schedule table to fit the design of the website. I could not really wrap my head around the things I found via google and I'm not too familiar with drupal theming in general.
I would really appreciate it, if someone could give me short instructions how i can add css-classes to the different table elements of the station schedule.

best regards

Günther