this thread has the info on how to upgrade and more...
http://forum.ppcgeeks.com/showthread.php?t=24979
here is HTC link for the ROM
http://www.htc.com/us/supportdownloa..._id=76&cat=all
here is the link to upgrade through microsd card
http://www.sprintusers.com/forum/sho...d.php?t=166460
"quoted from SU"
How can I upgrade if I don't have a Windows PC?
You can flash via your storage card:
- Format your SD card to FAT32 (the default 512 card it comes with works great for this, remmeber you will loose everything on the card, so don't do this if you don't have a spare SD to use, and cards bigger then 2gb won't work.
- Download and install WinRAR (
http://www.rarlab.com)
- Extract the .exe from the above link using WinRAR, and extract 2.nbh (it's a 107mb file or so)
- Rename 2.nbh to VOGUIMG.NBH and put the file on your storage card.
- Put the storage card in your phone and get into bootloader mode (power key + camera while doing a soft reset) it should say something about do you want to update, then push the powert button to start the update.