Slice the peppers into thin rings and remove the seeds. It's okay if a few seeds stay. You might want to wear gloves if your hands are sensitive to heat!
Add vinegar, water, sugar and salt to a saucepan and heat until the sugar and salt have dissolved.
Run the glass jar under hot water so that it doesn't break when the hot pickling liquid is poured into it. Add the sliced peppers and smashed garlic to the jar. Carefully pour the pickling liquid over the peppers and close the jar.
Refrigerate and enjoy after 10 hours and up to 1 month!