How do I fix this dread?
If the connected part is fairly new, sometimes it's easier to work the strands out of the knot one at a time than to rip all at once. Then it gets to where the rest will rip apart easier. I also grab the two connected dreads in between the connected part and my scalp when separating instead of the two ends. That way I can hold my hair still and not tug on my scalp while I separate. I hope that makes sense. If it doesn't I can make a YouTube video explanation.
if they are more maturely joined, the how-to barrellady mentioned using a blade or scissors will work. Only use one side of scissors to avoid any mistakes.