The Firmware update for htc one plus is released with lots of new improvements.the update is only Android 4.1 Jelly Bean but if you want to get Android 4.2.1 Jelly Bean version outside US, an AOKP ROM is available for you.
Requirements:
This is only compatible with the HTC One X+ International variant. US variants may suffer system failure.
- Battery level must be at least 70 per cent.
- Enable USB debugging mode on your phone.
- Create a backup of your personal information, settings, and data files on your device.
- Unlock the HTC One X+ bootloader to flash this AOKP ROM. Check this Unlocking Guide for HTC One X+
- Install a custom recovery app such as ClockworkMod or TWRP on your phone.
- Download the AOKP 4.2.1 Jelly Bean ROM for HTC One X+.
- Download the Google Apps package.
- Download the Fastboot files.
Flashing Instructions ::1. Connect your phone to the computer using a USB cable and transfer the downloaded files to the internal memory. Disconnect the device.
2. Turn off the device and enter the bootloader mode by pressing Volume down + Power keys.
3. Select "fastboot" and use the Power key to confirm.
4. Connect your phone to computer and let the drivers be installed. If your phone is not detected, use the HTC Sync Manager CD to install the drivers.
5. Extract the Fastboot files in a folder.
6. Extract the "boot.img" from the AOKP Firmware you have downloaded to the Fastboot file folder.
7. Open a command window in the Fastboot file folder.
8. Enter these commands: fastboot flash boot boot.img
9. After the successful kernel flash, disconnect the phone from your computer.
10. Select Recovery mode in the Fastboot mode of your device.
11. Create a Nandroid backup of the current ROM to restore it in case something goes wrong. Select "backup and restore > backup."
12. Perform a complete wipe by selecting "wipe data/factory reset" and "wipe cache partition."
13. Install the AOKP firmware by selecting "install zip from SD card > choose zip from SD card." Use the same with the Google Apps package.
14. Go back and select "reboot system now" and wait for the device to reboot.
15. Android 4.2. Home screen will appear after the boot bringing all the new Android experience.
Congratulations! Your HTC One X+ is now running Android 4.2.1 Jelly Bean using an AOKP custom ROM. Visit Android Legend for any comments or suggestions for the Android 4.2.1 installation guide.