1. It takes 5 yuan to change the lock cylinder at home, and it only takes about 1 yuan to do it yourself.

2. Lock cores can be purchased in JD.COM or other e-commerce companies. Generally, super B-class lock cores can meet the needs of home safety.

2. How to replace the lock core of the security door

1. There is an iron packing box outside the lock core. The two loose keys with mouths are for decoration, and the six keys in the small box are official keys, so the keys for decoration can not be used again after use.

2. There are two fixing screws on the handle plate inside the door lock, which is easy to remove. The handle on the inside has a knob, so it is disassembled later. When disassembling, be careful not to take off the square shaft on the handle. There is a small spring inside, which is easy to come out.

3. When disassembling, remove the handle outside first, and put it away in the order of disassembly, and don't take out the square shaft. But it doesn't matter if you come out, as long as you know the position of the spring. It's easy to find when you pretend like this. Just remember to disassemble first and then assemble. Pay attention to the fact that the small square shaft is not easy to come out when it is placed upward, so that it will be easier to install.

4. After the handle panel is removed, there are two lock caps at the lock core position. Note that this is installed backwards. The screw cap is convenient for thieves outside, and it comes down with a screwdriver.

5. There is a screw hole under the lock core for fixing the lock core. This is an old lock cylinder that has been removed. Note that there is no iron bar under it, so thieves may break it with tools. (Before buying a lock cylinder, remove the lock cylinder and measure the total length and the position of the middle screw hole)

6. The position where the screwdriver is aligned is the position of the lock cylinder screw. Sometimes the lock core is difficult to take off, just turn it a little with the key.

7. This is the correct position to install the lock cap, so thieves can't remove it with a screwdriver outside. Don't tighten these two screws too tightly to prevent the lock from being inflexible.