First off, turret and knob are interchangable terms.
Leupold can retrofit your scope with the knobs you want. Go to: https://customshop.leupold.com/
and you will be able to see all your options. Then call them up and ask them about what it might cost you to have your knobs changed. The good thing about sending your scope back to Leupold is that it preserves your warranty.
They can also change your reticle if you like.