Bus options include John McGinley Coaches & Bus Éireann. Neither one will take you to Dunlewey but John McGinley Coaches will get you closer. If you are staying in Letterkenny either bus service will get you there.
John McGinley Coaches will get you as far as Gortahork or Bunbeg, both about 15 minutes from Dunlewey.
John McGinley Coaches Route Map
Here are some approximate taxi rates to Dunlewey.
After the rate is calculated click on “See Fare Results.”