First, read the English article below.

This is an especially useful method for removing small-to-medium-sized dents, and you may have more of these then you think. Examine your car carefully to find them all. Dents can typically be removed using this method if they are located on the metal panels of the trunk, hood, doors, roof, or fenders, and are not right along the edges on broad flat surfaces. To achieve the best results, use this method on shallow dents that do not contain major creases or paint damage, and that cover a surface area with a diameter of at least 3 inches (7.62 cm). You will need a hair dryer, heavy-duty or thick rubber gloves for safe handling of the dry ice or compressed air in its liquid format, aluminum foil, and either a package of dry ice or a can of compressed air. You will need some of the following:  Heavy-duty insulated rubber-coated gloves. A full (or nearly full) can of compressed air. A package of dry ice. A hair dryer with adjustable temperature settings, such as "Low," "Medium," and "High," or "Cool," "Warm," and "Hot." Aluminum foil. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Xác định vết lõm. Đánh giá vết lõm. Chuẩn bị những dụng cụ cần thiết để xử lý vết lõm.