I'd tear down the whole building; as I'd be very surprised if the walls weren't full of bugs as well, similar to the American Embassy case.
http://www.nytimes.com/1988/11/15/world/the-bugged-embassy-c...
http://www.nytimes.com/1988/11/15/world/the-bugged-embassy-c...
US sold a Boeing 767 to China which was planned to be used by the Chinese President as the official jet, as expected, it is full of bugs.
http://www.telegraph.co.uk/news/worldnews/northamerica/usa/1...
Australia put bugs in the newly constructed Chinese embassy in Australia's capital back in 1995.
http://www.abc.net.au/news/2013-11-08/the-chinese-embassy-bu...
This article may be from 1988, but it seems somewhat applicable to current events.