As George stated, the inside trim can be removed and there is no sealant used on it. In reality, the inside cover and the outside cover are totally independant. When you remove the inside cover, you will see the inside of the attic space. The actual leak might be occuring anywhere in the roof and only coming thru the ceiling at the shower skylight. But most likely it will be the outer skylight that is the problem. You really need to fix the leak from the outside. Using sealant from the inside will force the water to saturate more of the roof plywood, move the leak to another spot that now stains the ceiling panel and long term weakens the rubber roof adhesive.
If you can locate the actual leak with the inside panel removed, then find a way to capture that water and/or direct it down the shower drain, til you can go outside and fix the leak.
Texas Baptist Men-Retiree Builders member since '01
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