Thanks ToledoJust loosen the little set screw with a hex key and then use the spanner wrench to tighten the top collar down. Clockwise to tighten and counter clockwise to loosen. Don't forget to retighten the set screw when you're done.
Do I have to do any measurments prior to adjusting the coils? As far as I remember, 4 complete spins clockwise equals 0.5". For 285/75/16 2.5" is enough?