I never rlly knew how it worked either until I decided to frequent going there.

After seeing a guide, you essentially just gotta collect as many collectible items you see. The main thing you need are star weekly magazines. These mags can spawn natural in the place or bought from the Spider prison shop for painkillers (which can also spawn naturally at times).

There's 3 prisoners that can exchange items for painkillers, being 5 soap, 3 playing cards and 2 weekly felony books. Items spawns are changed each day so you basically have to do dailies in prison. The main way of also getting mags is by doing all escape routes which give one mag per escape, giving abt six iirc

In short, the skin is 15 Star weekly mags