I've never had problems with the home button on my Verizon iPhone, but if you do, you should check out this repair post from iMore's Allyson Kazmucha. Kazmucha, who founded the repair company PXLFIX, shows you how to remove the back cover, disassemble the internal components and pull out the home button on your CDMA iPhone.
It's not an easy process as you have to dig through the battery and the logic board to get to the home button. The iMore post has detailed images, which should reduce your chance of making a costly mistake. As always, if you do decide to take apart your iPhone, proceed at your own risk.
Apple iPhone 4