Make sure the stereo is on the setting “BT AUDIO” then on your phone go to Bluetooth settings and wait for KD-X482BT to appear and click on that on your phone. It should then come up saying “pair” on your phone click this button then also push the volume button in to accept the pairing on the stereo.
If this doesn't work, click on "forget this device" on your phone settings and try again. The name of the Bluetooth should be “BT AUDIO” or "BT0714". When you click on 'paring' you'll need to enter the PIN which is 0000.
The instructions above are similar for other Spaceships campervans (all have Bluetooth), although a different device name might appear in your phone's Bluetooth device list.