Everyone gets a 1’x1’x6’ cell to luxuriate in. If my memory serves..

I think you just start pitching people in, and the compression happens naturally as the people pile up.

Good news though. Without using any math or science, my AI determined that the people at the bottom will be under enough heat and pressure to become oil, or diamonds or both. Just put a spigot at the bottom so we don't lose that economic value in the bodies of the people we've systematically crushed to fund our lavish extravagant lifestyle.

It's a sort of human pyramid meets human centipede.

I think you just walk into the fluidic solid walls, like the Homer into the bushes gif, except face first, where you are slowly enveloped by the acceptance of the warm loving collective.

You're run through a grinder to join the mega-meatball.

Even though those are very different procedures, I fail to see how the outcome could be any different.

I believe the first step would be dehydration.

Both.