Did the past owner have it set up for his weight correctly? Maybe you will have to do nothing.
If he did have it set up for his weight. My first guess would be to check the adjustment on the rear shock with that metal adjustment plate (if it has one). Then to do the block thing as stated by barkmulcher above.
triplepower- Posts like that aren't appreciated by the poster nor the reader. So keep them to yourself. SF doesn't encourage brand bashing.
Check the sag in the suspension when you get on it with full gear. Should be acouple inches at most. If less then too stiff. Might need lighter torsion springs. Less preload on center shock will increase steering effort on skis. Need some preload but maybe you can get away with less. Most likely mod the previous owner would have done is upgrading the torsion springs.
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