If your HK45c is a factory V1, you don't swap out any stock springs to make it a Light LEM. You'll just need the LEM kit. If yours is a Heavy LEM, then you'll need a few springs.
Contact skullbox. He's in the vicinity of Orlando/Kissimmee area. I am a little farther away but would be glad to help you install the LEM kit (Light or Heavy version) if you're willing to drive 60 miles west.