If it is your first time at Hallym University, you might not know how to get to Chuncheon Station; it is the closest train station to Hallym.
If you are walking, it is going to be about 20~30 minute walk, but you can also take bus 12 (takes 5 min) to get there as well.
From Chuncheon Station, you can take ITX to Yongsan Station, which is in Seoul.
Please check ITX timetable in Korail Website