Step on all symbols on elevator at the same time. Find the same symbols as the elevator on the ground and step on the symbols in a certain order. Get a sniper rifle and shoot the orbs in each of the dragons mouth. The orbs will appear in the spawn area by the door. Shoot the orbs with the sliquifyer until they spin. (Every clip of the gun for each orb.) After getting the orbs to spin, get the trample stamp and shoot zombies in the tower on the roof. (sacrifice) (The supports of the tower will glow blue.) Then get the galvaknuckles (for energy) and punch the tower until the achievement is unlocked and you receive all perks. (except Phd Flopper)

Sorry not step by step and i think it should work for you.