How do you change class late-game?

Usually one can change class by going to the Coon lair, sitting down and talking to Cartman. However at a point in the game that is no longer possible (when you unlock all powers).

However, despite having all powers you don't have all classes, which means you can't take pictures with all the people at Raisins, preventing the selfie completion.

Is it possible to change class after

Mitch Conners

is revealed to be the main Villain?

Solution 1:

Managed to figure it out.

Turns out your class changes with every power equip, meaning that if all your abilities are that of a Blaster, your class is perceived as being Blaster. If you combine powers from 4 different classes, you'll be perceived as part of all of those classes.

This also enables the Raisins' selfies.

TL;DR? To change class, equip a power of the desired class