Slash paid tribute to his late stepdaughter Lucy-Bleu Knight, who passed away last week at 25 years old, RadarOnline.com can reveal. The legendary Guns N’ Roses guitarist, 59, took to Instagram to remember her in a heartfelt post which read: “My heart is permanently fractured. I will never ever stop missing you & remembering what a beacon of happiness, laughter, creativity & beauty you have always been. & still are. The brightest light in the lives of so many that loved you so much. I find solace in the hope that you are at peace now. I will love you eternally. #LBK” Other celebrities chimed i…