The takeoff is just northeast of the corner of the lake, here:
http://ja.is/kort/#x=367964&y=378037&z=6
Park opposite the summerhouse, walk east along the foot of the slope, following a line of small yellow poles. After about 700m, you should be below a broad gulley (couloir) with a grassy patch at the top. Turn left, straight up the slope.
The launch is in a gap in the rock band and is a bumpy grass patch about 50m across.