Written and reprinted with permission by Amy. Thanks!
First picture: The pull looks like a small nub. Open up your safety pin (easier for me to hold than a straight pin or needle). Gently tug on your pull so you can see if it comes from a thread that goes down the length of the wrap or the width. Try to untangle the thread if it has twisted back on itself.
Second picture: My loose thread runs from one rail to the other. You need to decide if you want to redistribute the extra length to the left or the right. I'm going to the left. I gently insert my needle into one of the threads to the left of my pull. Carefully, I gently tug to see if it makes my pull move. If not, I try another thread. If it does, I gently tug so the pull becomes a tiny little loop.
Didymos usually has two threads that run in tandem from one rail to the other. In this pull, only one of the threads was pulled out. Keep working your way across the width of the wrap making tiny loops. I wish I had a different lens for my camera so I could get you a better close-up shots. The longer the pull, the more little loops you make. Since my pull was small, four loops ate up all the extra length. You want your loops to be relatively small. The theory is that with a little use, the loose thread will work itself back into the weave.
Third Pic: One last loop is being made.
Last Pic: Gently pull on your fabric diagonally in both directions. All of the slack is worked back into the weave.
Didy stripes are one of the harder wraps to repair because the weave is more closed. Didy Indios and Waves are much easier to repair because each thread is more able to move around and slack is quickly absorbed. Conversely, that is also why Waves and Indios are more likely to get pulls in the first place.