Water Marks

[Harris4]

How in the world do you cleanly cover water damage that has occured around the roof vents?  

[handyman]

Im guessing your talking about the inside what I did to mine around the T.V antenna crank where the ceiling had rotted was us 1/8" plywood cut two inches more than the damage then beveled the edges and then counter sunk fore holes, then glued it over the damaged area and used four small screws to hold it in place then painted it and the rest of the ceiling it tured out great and is stronger than the rest of the ceiling going around a vent should be the same