Access to the top of Galdhøpiggen is not especially hard: from Juvasshytta (1850 metres above sea level, 5 km from the summit) it takes about three hours up (including about 45 minutes to prepare for crossing the Styggebreen glacier), an hour at the top and about two hours back.
Galdhøpiggen can also be hiked from the Spiterstulen lodge in Visdalen, with a technically very easy, but still somewhat strenuous climb of 1300 m - nearly 4000 ft.