Only Fan leaves starting to turn yellow?

No do not remove any leaves, your plant is feeding itself from those leaves because it is hungry for potassium. You still have another 3-4 weeks to go, so don't start flushing too early. Nothing at this late stage that you can do to "fix" this before harvest time. Adding a P/K booster or upping the dosage if you are already using one, will slow the yellowing down, however, the damaged leaves will stay damaged. Remember too, what is showing now in the leaves, is a direct reflection of what was occurring in the root zone 2-3 weeks ago.