You can take the MTR from Ching Yi to Lai King, then get off at admiralty station.- then following the sign to Ocean Park bus stop
or you can take the MTR to CEntral, then change to HK line to admiralty station - then follwing the sign to Ocean Park bus stop.
Going back from Admiralty to Lai King, then Change to Ching Yi, this is the easiest way and you do not need to walk so far at the Central station.