By Bus: 
Bus 24, 28, 31, 31E or 36E towards Snarøya, alight at Fornebuparken

From Oslo Airport, Gardermoen:
Take the aiport train (flytoget) to Lysaker, then change to bus 24, 28, 31, 31E or 36E to Fornebuparken 

From Oslo S (Central station):
Bus 31 or 31E to Snarøya from Jernbanetoget