Caution: That is a guide for the At&t version of the G2. OP is trying to install VZW G2 software, so hoping he is using the VZW version of it.
So, you HAVE been able to update, or you have not? How are you trying to update if it is not working for you? You tried to use ioroot25 on 4.2.2 or 4.4.2? What was the error or where did it stop before failing? Have the correct drivers on the PC?
In general, the more details we have, the easier to help. Just saying "It didn't work" is not helpful for troubleshooting.
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