Algarve to Lisbon Transfer

Hello! We spending a week in Portugal. 2 nights to start in Lisbon and then will be staying in Algarve for 5 nights then flying back out of Lisbon at 11am. What is the best method of transferring between Lisbon and Algarve? In particular, given we have a morning flight home and need to get back up to Lisbon to fly out at 11am. Thanks for any help you can provide!