Complex sentence: In both cases, the fencer is not allowed to disrobe in order to change cords; this leads to the common practice of replacing the body cord by tying the new cord around the defective cord and pulling it through the sleeve.
Split into simpler sentences: In both cases, the fencer is not allowed to disrobe to change cords. This leads to the common practice of replacing the body cord by tying the new cord around the defective cord and pulling it through the sleeve.