Wait until the bird leaves and cover the stove vent with a stove vent guard or screen. Perform this step only if the bird has not created a nest. If a nest is present, start at Step 2.
Straighten out a wire hanger leaving a small hook on the end. Once the bird and its babies leave the stove vent, immediately place the hook end of the wire into the vent. Pull pieces of the nest out of the stove vent.
Continue pushing the wire hanger into the vent, hooking pieces of the nest and pulling it out of the vent until you have removed all traces of the nest.
Install a stove vent guard over the stove vent, using the screws included with the vent guard. The guard will prevent birds from entering the stove vent in the future.