Guide to remove and replace part fan?

[Tom55]

One of the three part fans apparently moved too close to the glass clip and one of the tiny fan blades chipped off. It still works but there's a horrible high pitched buzzing noise now

Is there a guide to remove/replace a fan or to disassemble the hotend? - Just want to check before I start unscrewing things. Looks like I'll need to remove at least one of the arms to access one of the screws.

Thanks
Tom