Take out a soft blanket and spread it on the ground. If placed directly on the ground, it is easy to be scratched by some particles on the ground. We need to put the damaged bumper on it so as not to scratch the bumper and avoid secondary damage to the bumper.
First, visually check the scope of the depression and get a general idea. Then touch the sunken part by hand and repeat it several times to determine the final damage range, and then make a reasonable repair plan. Be sure to determine the scope of the depression, so that we can have a sense of direction when maintaining.
Take out the heater, then turn on the power supply, turn on the heater, aim at the concave area, keep moving with your hands, and don't blow in one place, so that the concave part of the bumper is heated evenly. There is another point that needs everyone's attention. The distance between the heater and the bumper must be controlled between 10 and 15cm, neither too close nor too far. Too close will easily hurt the bumper, too far will lead to insufficient heat.
After blowing the heater for a while, turn it off, put it aside, then take out the screwdriver and press the concave part back from the inside of the bumper. What we observed in the bumper is a bump. All we have to do is flatten the bulge and pay attention as soon as possible. Don't wait for the concave part of the bumper to get cold before pressing it. That will be very laborious, and it will also reduce the bumper pressure marks and affect the appearance.
After leveling, we go back to the concave part of the bumper and touch it repeatedly to see if it is flat. If there is still a small dent, simply repair it until the bumper surface is flat. The repaired bumper should be put on the shelf, so that the whole concave plate repair process is over. I hope it will help everyone!