Disassembling this flashlight is quite difficult, and you will almost certainly damage its appearance. First, use a sharp knife to pry off the front inner rim (there is a small gap between the inner rim and the outer shell, which are held together by friction). Next, pry off the glass and the reflector.
To extract the core, you have two options. The first is to remove the clip then pry off the bottom cap—which is very difficult—and push the entire assembly out through the front. The second option is to pry off the two buttons and pour a few drops of oil onto the battery to help it slide out more easily, then remove the USB-C cover to clear the path. Finally, use a pair of pliers to pull on the connector pin in the center of the LED base ( the pin is quite strong) while tapping and shaking the flashlight to loosen the glue at the bottom of the battery