There should be clamps that connect the exhaust pipe of the dryer to the vent.
How to open dryer vent on roof.
A better roof termination.
You should be able to use your screwdriver to remove the screws holding the vent in place.
Go to the back of your dryer moving it if necessary.
Once you have done this the vent cover should come off easily.
Next remove the vent hood retaining screws and pull the vent hood and stub pipe out of the wall.
Use a screwdriver to release these so that you can vacuum.
Difficulty cleaning dryer vent.
Disconnect the hood from the stub pipe and toss the hood.
Dryerjacks are the first roof vents designed to meet the more stringent venting requirements of dryer exhaust systems.
When it does a roof based dryer vent can contribute to damaging the roof.
Then go outside and remove any siding trim pieces from around the vent hood.
You can put the tube of the vacuum directly up the vent.
This may lead to leaks and other costly damage.
Before climbing up to the roof get behind the dryer to vacuum out the vent.
Unlike the vents shown above left the dryerjack affects airflow by less than 01 water column inches of pressure.