Memes

If you know how to re-wire stuff properly, it's conceptually an easy process (some devices can be tricky to take apart).

For example, on that toaster you can replace the cable with a longer one, put a new plug on it if that gets worn out, or if absolutely needed splice the cable with another one (that's for when the device can't be opened up for some reason)

Unplug toaster before cutting the power cord, or any other maintenance, such as cleaning the 3 years of crumb its collected.

The most preferred method is to replace the entire cable, the wires connect inside the device somewhere, probably with simple screw terminals. Replace the whole cable and you don't have to worry about any weak points in the splice or insulation, because there are none.

The danger is when you don't know how electricity and wiring works or get lazy and take shortcuts.

There's a bunch that can go wrong, some of them have potentially life ending consequences, which is why it's a bad idea to work on electronics...unless you take the time to learn how they work and be smart about it.