Fly to London Gatwick or Heathrow Airports. Then take a train. Kent is a large county, but depending on which part of Kent you are going to Gatwick might be better as you will be able to avoid travelling via London with a resulting lower train fare

www.nationalrail.co.uk

Get a flight to Gatwick and then get a train to wherever in Kent you are going.

The obviously easiest way is to fly to London then take a train to wherever in Kent you want to be.

Fly

https://www.rome2rio.com/s/Belfast/Bexle...