One of a number of ways would be to cross Waterloo Bridge, head through the Elephant & Castle and Camberwell, past the Maudsley Hospital and then through Dulwich to Crystal Palace.
At Crystal Palace you head down the hill through Anerley, past the traffic lights and over the railway past Elmers End station. Take the left turn at the traffic lights and then 200 yards on at a roundabout bear right as signposted to West Wickham.

We are on the left just before Eden Park station.