How to clean mold (?) on sky light??

Hi yall I just moved into this place with a skylight in the bathroom and I didn’t realize it had this mildew/mold buildup until I moved in. I tried cleaning it this morning using a rag with vinegar and then bleach tied to a swiffer duster (it’s quite high up, and I only had a step ladder) but I only got to fade it this much. I’m worried it might pose a health concern but I’m not sure how to clean it or if I need to get help from someone else to clean it. My bathroom retains a lot of moisture so I don’t think this is the end of it. Any non-judgmental advice is appreciated ❤️