Answer:
You can get to Libya from the following airports: Heathrow, Gatwick, and Manchester. There are also some airlines inn other airports that take you there to.
(1) - You can get to Libya by plane from any international airport. You would most likely land at Tripoli Airport.
(2) - you can get to Libya by sea from France, or more commonly from Italy. Libya receives a number of cruise ships from around the world, most of which dock either at Tripoli seaport or Benghazi seaport.
(3) - you can get to Libya by car or motorbike, via its two main land border: Ras Jdayr (the Libyan Tunisian border) and Emsaad (the Libyan-Egyptian border). Libya receives a large number of tourists and travellers who cross Libya overland between Tunisia and Egypt, in their way to or returning from South Africa.