I assume you mean via the Remove button for the device on the Z-Wave Details page.
Post a screen shot of the ghost from your Z-Wave Details page. If you have more than one neighbor listed for the ghost the Remove option on the Z-Wave Details page will usually fail.
If you haven't yet, reivew the approaches covered in this topic...
For future Z-Wave use you may want to move to Z-Wave LR (Long Range) devices, which don't depend on a mesh, and if they do have problems can't affect each other. However, Z-Wave LR is still very new on HE and there are still some kinks being worked out.
