1. First, take out the utility knife and locate the latch at the end. Pull it out forcefully.
2. Then, slide the middle slider and the blade out of the knife case together. The blade and slider will come out together. However, the blade is held in place by a retaining point.
3. You cannot remove the blade directly by lifting it upwards. You need to hold the blade and slider at a 90-degree angle and then pull the blade upwards.
4. Next, take out the replacement blade. Note that blades come in different widths; make sure the replacement blade is the same width as the original. Then reassemble it following the disassembly method.
5. Finally, replace the retaining clip at the end of the utility knife and tighten it securely to prevent the slider from sliding out. The utility knife blade has now been replaced.
Notes:
When using a utility knife, usually only the tip is used. Cutting, carving, and marking are its primary functions. However, the blade of this type of knife is quite brittle, so it shouldn't be extended too far when used. Furthermore, the hardness and durability of the blade (these are two different concepts in utility knives) vary depending on the material of the blade.
Many utility knives have creases or bends to facilitate breakage, but these can be dangerous for left-handed users; extra caution should be exercised when using them.
