To remove a tough stain from carpet, you will only need ammonia, hot water, a spray bottle, a stack of clean and color-safe towels, and an iron.
It would be best if you also preheated your iron, then mix one-part ammonia and one part hot water, spray the mixture onto the carpet stain, and put a clean towel on top of it.
Now, you place the hot iron on the towel and move it around slowly.
Finally, spray more of the mixture on the stain and repeat the process.