Remove nails take out old roof jack attach new roof jack if you have squirrels in your area there is a good chance the lead roof jacks on your home need to be replaced.
How to remove a roof vent cap.
Remove the fasteners that secure the rain cap to the top of the vent pipe with a screwdriver or nut driver.
Video turorial on how to change out a plumbing vent boot.
Works for any size pipe.
Go in the attic find the dryer vent pipe and follow it to the roof.
Access the roof using an extension ladder.
They all have a screw under a dab of caulk.
Roof jacks fit over plumbing vent pipes that protrude through the roof to keep them from leaking.
Yep i was up on the roof the other day eyeballing my vent caps.
The cap shingles often are installed on top of a continuous ridge vent.