How does one add more string heddles?
You go to the back of the loom and pull out the little plastic wormy thing which is a blocking mechanism to keep the harnesses in their proper place. Pull out the rubber thingme and then you lift up the back shaft slowly and eventually you will be able to lift out the harness. Then you pull off the plastic ends and add or remove heddles. Next, you pull off the plastic ends and add or remove heddles. When you are finished you can hang the whole harness up on top of the loom so you can get at other shafts. You put them back in the same way you took them out.