well i don't really know b/c my nobs turned easily for me, maybe b/c they are new lights. And to make it a little easier for you, the big nob that is made of plastic with a screw in the middle does nothing. Don't try to turn that one just try to turn the nob made of metal. You could take out the big plastic nob if it is in your way b/c i did that and then turned the metal nob with my fingers. It was a little hard to start turning it but once it started it was easy to turn it the nob after that. Try it and let me know how it goes maybe i can get some pics up on how i did it if you want them.