mini-PCI card of very easy to swap out provided there is an access panel. All of my laptops and tablet PC's have an access panel and the card just pops out after disconnecting the antenna.
Make sure you get the same style card with the same antenna connectors. IF you have Mini PCI make sure you do not get a Mini PCI-E card.
Other then that, make sure you have the drivers for your OS and new card ready to go.