How to access internet wirelessly on WD Live TV device (does not have WiFi)

I have the WDBAAN0000NBK-00  WD Live TV media device downstairs and is too far away to use a network cable. How can I connect it wireless to the router.

Thanks

You buy a compatible wifi adaptor.
http://wdc.custhelp.com/app/answers/detail/a_id/3805/kw/wifi%20adaptor/session/L3RpbWUvMTM1NDYyNDAwNy9zaWQvNm9VMkpVY2w%3D#wireless

Beware - you must get the correct adaptor as listed. Manufacturers are always changing the chipsets internally without changing the model number.
Good luck in finding the correct adaptor and try and get it from a supplier who accepts returns if it fails to work.

The revision / version number is just as important as the model number. Unfortunately most suppliers do not mention the revision / version number in their ads.