Welding points on Flex cables

Hi everybody,

On recent iPhone models, when you buy a remplacement flex cable for power or volume buttons, sometimes not all the parts come with the flexcable and there seems to have some small welding points. For exemple on the iphone 7 mute button there is two solder points, but I’m talking more about real welding points, for exemple on iPhone 11 pro power button. How do you dis-assemble and re-assemble such parts when there’s not the full metal bracket that comes with the flex cable ? I’m not talking about the ones that are just glued on the bracket…

Thank you in advance and happy new year !