How do....
The short answer is lots!
That said I off road my double cab with approx 200kg of weight in the back. made up of off road 'must haves' :lol: & various off bits n bobs.
I'd actually put the weight as far back as possible to get the most effect. A couple of big bags of sand??
Slap on Mud terrains, even on the standard tyre size they go well off road!