Apple today has released a new version of iOS for Verizon iPhone 4 users. This special release of iOS 4.2.8 is to fix much talked about tracking issues for Verizon iPhone 4 users.
To update your iOS on Verizon iPhone 4 CDMA to iOS 4.2.8 simply connect your iPhone to your computer with USB cable and connect it to iTunes. Once done you will get a message Download and Update. Click on that and your iPhone will be upgraded to iOS 4.2.8.