TKD is a distance striking style. To defeat, you have to get inside their reach. Just like the first technique, if you get in close, the attacks don't get a chance to build up power and dont really hurt. You have to either be really fast and nimble so you can move it without getti g hit at full extension, or you have to learn to take the hit. Guard your vitals and suck it up.
Once you're inside his guard, any number of grappling or short-range striking techniques will take him out. Nobody fights well after a throat punch or once you've jammed your thumb in his eye. Fingers jammed up under the short rubs or into the solar plexus will really fuck up his day.
A low kick to the side of the knee will break/dislocate it. If you can't stand or walk, you can't fight. Hell, grapple and put him in a choke hold and wait for him to go limp. Fight's already won if your opponent can't breathe.