Fixing A/C duct leaks

[Berniross]

While installing a turbo/maxx fan in the bedroom I discovered a lot of cool air between the ceiling and the roof. The A/C was running. I have read on this forum about a lot of people finding leaks in the ductwork and fixing them. My question is how do you get access to the ceiling ductwork to even check it?

[Stan]

The only way i know is to remove the grilles and using a bright flashlight and mirror you can see pretty good.