i just had this problem and unfortunately for me i had to cut off my top main cola of my best plant, yes i gave it a proper burial and said a prayer for wasting such a beautiful gift from god... sorry kick myself for that everytime i think of it... the best thing you can really do is if you absolutely have to, cut what you need to and do it early as possible so you stress as little as possible. and use some string and gently tie the branches out of the way if that's possible, but there's not a whole lot you can do besides move them out of the way, or pull the light up, which for me was impossible. i will say that even with 2 tops getting burnt, cuttting the main top and having a couple still growing into the light reflector as we speak, the plant is THRIVING, it doesn't give a damn how close the light is, so goodluck with that man and do like me, i marked the "point of no return" in my grow room so i know when i HAVE to start them flowering, haha!