how to replace wifi aerial late 2011 macbook pro

Is it possible to replace the wifi aerial an a late 2011 15" macbook pro without replacing the entire screen/cover. Specs are: OSX lion, version 10.7.5, processor 2.2 GHz intel core i7, 8GB . I have replaced the wifi cable, and have had unit checked out at IMAC store and was told the wifi card was good, but the aerial was not and they said the entire screen had to be replaced at a cost of over $600. This can't possibly be true as there has to be a replacement aerial available, apple surely wouldn't design something like this. Unit keeps dropping wifi unless it's less than 20 feet from the source. thanks for any help