Yes the wireless Network adapter can be replaced.
[guide|166533|Click here.]
This is for the battery but shows you how to open the case and remove the battery. Never do any interior work without disconnecting the battery.
Go to Step 4 and the Adapter is right in the centre of the photo.
But first of all does it appear in Device Manager ? Is yes then right click delete it and then open "Action" menu selecting "Scan for hardware changes" and Windows will reinstall the driver.
Does it work now. Yes or no? If no replace the adapter.