How to speed up the disassembly of large LEGO technic sets?
&quot;Reverse Construction&quot;
Most Technic models are built in a modular fashion. This particular model (42043 Mercedes-Benz Arocs) is no different, from the instructions you can tell it has been built in the following order: Engine/Chasis, Cab, Wheels, Truck Bed and finally the Crane.
Large sets often use red pins to join together major components. Therefore the best way to deconstruct a Technic set is to do exactly the opposite and work your way back through the instructions or at least the 'major components'.

Major components (for lack of a better term) are usually highlighted in the instructions and typically have their own numbered bags. Below you can see the truck bed.

The truck bed consists of a number of sub-components such as the truck outrigger.

Working backwards through the instructions you can either tackle the disassembly on a piece-by-piece basis or on each sub-component.
Use a Pin Pusher
Disassembling Technic models has always been a painful experience for me, particularly on my thumbs when removing the many, many pins and axles used.
I like to use a 'Pin Popper' to easily remove most pins. It's essentially a axle (Generally the longer the axle the better). I like to put a few Brick, 'Round 2 x 2 with Axle Hole' at one end to use as a handle and to stop the axle digging into the palm of my hand.

I have also started to use an alternative pin-pusher design to speed up the process.