As Piloon has so kindly mentioned extending the top link will aid in digging in the snowpack.
Slowing down in reverse if you have a reverse creeper gear works very well also as the open
augers will be better able to chip away at snowpack that has melted and become more dense
from freezing.
Extending the lower link arms will be a potential problem as you have to be very careful about
elevating the snow blower too high as you can damage/destroy the tractors PTO stub shaft,
the PTO shaft and also destroy the gear box.
There are many descriptions examples showing how you should manage your rear mounted snow
blowers lifting height/range here on the forum to assure it does not go above the tractors center line
too high or too low which will also damage the tractor and or the snow blower
AS TerryR has mentioned a 3 point hitch will only be used to lift an implement like a snow blower
as the tractors hydraulic system for the 3 point hitch is considered a single acting hydraulic circuit
which means is has pressure only in one direction/upward for the hydraulic system.