Easy steps:

1) Download a free autoclicker from the internet.
2) Start Lootbawx.
3) If you received the revolver item from any lootbox, choose it from the inventory
4) Take the revolver from the wooden desk, now you can use it.
5) Now activate the autoclicker and shoot the books or anything else.
6) Idle now and get all six achievements until you reach 100k points.
7) Enjoy! :)