Labuan has an airport with domestic flights, including connections to Kuala Lumpur and Kota Kinabalu. The airport is close to Labuan town and only a short drive from the war cemetery.
Ferries link Labuan with Sabah and Brunei, though schedules and routes change more often than travellers would like. Check the current timetable before building a tight connection, especially if you are using Labuan as a bridge between Kota Kinabalu and Brunei.