HTC is working hard these days to bring Android 4.0 Ice Cream Sandwich (ICS) to its older devices.  One HTC device getting the official Ice Cream Sandwich update is the HTC Rezound, although official pronouncements from HTC say that the device is not among the first batch of handsets to receive official ICS OTA upgrades.

Thanks to a leaked firmware (version 3.11.605.22), owners of the HTC Rezound can upgrade to stock ICS firmware, albeit a release candidate and not a final release version for OTA distribution.

Leaked firmware version 3.11.605.22 includes a handful of new elements that HTC has added to the popular Ice Cream Sandwich.  These added features are known to improve the Rezound’s overall performance and speed.

Apart from fixes for issues in earlier releases, other notable features of the leaked ICS 3.11.605.22 firmware include the following

• Android 4.0.3 Ice Cream Sandwich
• CMAS support added
• IPv6 over eHRPD supported
• UI updated to Sense 3.6
• Caller Name ID app added
• VMM/BUA plus updated
• New storage UI (under settings menu)

Caution

• Take note that this leaked firmware is official from HTC.  But, it is not the final version for OTA update.  So, expect several bugs and issues, which expectedly will be ironed out in the final version.
• If your HTC Rezound is rooted, flashing this firmware will bring it back to an unrooted state.

Requirements

• HTC Rezound
  • must be running on stock firmware (i.e., non-custom ROM)
  • must not have an unlocked bootloader (i.e., bootloader must be locked)
• Fully charged battery or at least 70% battery left.

Instructions

1. Download the update package from here, here, or here(rezound_ics_androidpolice_3.11.605.22.zip, md5sum: 58b0f42defc689650ddd5128f195dc7d).  Save the file to your computer without extracting the file.
2. Rename the downloaded ZIP file to PH98IMG.zip.
3. Connect your HTC Rezound to your PC via USB cable.
4. Copy PH98IMG.zip to the phone’s SD card (i.e., /sdcard).  Do not place the file inside any subdirectory.
5. Disconnect your phone from your PC.
6. Switch off your phone.
7. Reboot the phone into bootloader mode. You can do this by pressing and holding down the Volume Down and Power buttons until you see the HBOOT screen.
8. Once in HBOOT, your phone will automatically detect the update file and will automatically apply the update.
9. Your phone will automatically reboot once the update is completely applied.

Congratulations! You have successfully installed Android 4.0.3 Ice Cream Sandwich and HTC Sense 3.6 on your HTC Rezound via the leaked firmware build 3.11.605.22.