Disconnect the vent tube from the problem vent in the attic. This is usually just a few screws. Set the screw aside for reuse later.
Climb onto the roof and locate the vent that is causing the noise. Lift up the edges of the surrounding roof shingles so you can see the edges of the vent. Cut through any sealer that may be present. Remove the screws holding the vent in place. Remove the old vent.
Purchase a new vent that has the same size opening as the old vent. The new vent should have either weighted or spring-loaded flaps. This is what keeps the wind from picking them up and causing noise.
Install the new vent onto the roof using the opening from the old vent, sliding it under the shingles. Secure with the screws included with the vent. Load the caulking gun with roof sealer and seal all the edges of the vent.
Go into the attic and re-attach the vent tube to the vent. Use the same screws that were removed earlier.