How do I get rid of weeds in my grass?

Sprinkle "Preen" onto the grass. It is a commercial product that helps grass grow but kills weeds, sort of like weed and feed. It works quite well.

put boiling water on them.

Hi Ophelia,

If they are single plants, you can put straight white vinegar on them or boiling water. However if they are small plants that spread, I recommend a "weed & feed" product. It is my understanding that "Preen" is a pre-emergent which means it will stop new plants from growing but it doesn't kill plants that have already sprouted. It's possible Preen has a new formula that I don't know about but please read the label before purchasing any product. The best time to use the product is spring & fall so you can start now and repeat in the spring. I hope this helps. Wishing you the best.

Here's a post that might help - https://chascrazycreations.com/home-made-weed-killers/