Sabrina,
I'm with Sue - don't trim the plants back. They need their "solar panels" to generate carbohydrate. I think that's why they're called leaves, because we're supposed to leave them.
They'll sort themselves out, and the nastiest old ones will "age-out" on their own. Meanwhile, the plants will do better with them. I don't usually pull leaves unless they're half-yellow. I started feeding a few weeks ago and have quite a few plants with slightly floppy foliage, but they'll self-correct with time.