I had difficultly removing the cable strain relief grip. It ended up being easier to just bend back the wings of the metal frame. I reversed the process to reinstall it after recapping. Let me know if there is a better way.
I use a small parallel clamping wrench on the underside of the strain relief to remove it from the PSU. With a tight enough compression of the strain relief, it can be wiggled upward and out of the case.
