Just changed batteries. Having difficulty reinstalling on ceiling. Mounting bracket same diameter as light unit. Can't seem to insert unit in bracket.

Hi Don, Thank you for reaching out. It seems as though, you may need to make sure that the brackets are aligning correctly with the unit to insert. Please give our customer service line a call so we can help walk you through this situation, 877-298-9082. I look forward to hearing from you. Best, Aliece