Getting here is straightforward if you take it one step at a time.
First you need to get yourself to either Malaga or Granada
By far the easiest and cheapest way is to fly direct to Malaga which is served by many budget airlines.
If you are coming from the UK you will find details of Malaga flights HERE
Currently there are no direct flights from the UK to Granada
It is also possible to travel by train but it is expensive.
If you are travelling by train to Granada you can be collected at the station by arrangement.
See this link for comprehensive details of travel to the Retreat via Malaga