I think i found a google-cache of a guide here and it didnt work all the way to the end. Quoting it here just in case:
How-to: Flash Orange SPV e650 with RUU_Vox_HTC_WWE_1.34.405.1_184.108.40.206_03.10.90_Ship.exe HTC S710 firmware
This guide will do a step-by-step approach to successfully flashing your Orange SPV with the latest HTC S710 firmware upgrade (aka fixing the Invalid Vendor ID problem).
You need to have Winzip and ActiveSync installed to complete this guide.
IMPORTANT: Please follow each step (even if you think it's obsolete) or it will not work.The risk is entirely yours !! Don't blame me if you brick your phone
Reset phone to factory defaults:
Resetting your phone to factory defaults will DELETE ALL contacts information, calendar etc etc. Make sure you have made a backup of this data before proceeding.
1. Make sure your phone is turned OFF.
2. Press and hold soft1 and soft2 keys. (The menu keys above the 1 and 3 keys)
3. Press and hold the power button for around 1 to 1.5 seconds. Then release the power button. But keep holding the soft1 and soft2 keys.
4. The phone boots and asks to press the Send key to restore to factory defaults. Keep the soft1 and soft2 keys pressed and press the Send key (the key with the green phone icon).
The phone will now reboot and will be now reset to factory defaults. This can take a while, be patient. Wait until the phone has fully restarted before proceeding with the next steps.
Unbranding and unlocking the phone
Now it is time to unlock the phone so it will run unsigned applications (which is needed for the actual firmware flashing)
1. Connect the e650 to your pc via active sync
2. Download MoDaCo_SPV_E650_de_Brand___Fix_Pack.PREP.CAB
3. Download MoDaCo_SPV_E650_de_Brand___Fix_Pack_0.5.CAB
4. Download RemoveSecurity.CAB
5. Copy all three CAB files to your phone.
6. Start explorer on your phone and run and install the MoDaCo_SPV_E650_de_Brand___Fix_Pack.PREP.CAB file
7. Next run and install the MoDaCo_SPV_E650_de_Brand___Fix_Pack_0.5.CAB file.
8. Reboot your phone
9. Once your phone is rebooted run and install RemoveSecurity.CAB
10. Reboot your phone.
11. Download SDA_ApplicationUnlock.zip
12. Run the SDA_ApplicationUnlock.exe inside the zip file. You should get a message that your phone has been unlocked.
13. Reboot your phone
Flashing the phone
Now that you have de-branded and unlocked the phone we can start the update process.
1. Remove the SD card from your phone.
2. Connect the e650 to your pc via active sync
3. Download Vox USPL- CID BYPASS.zip
4. Download Vox-USPL-RUU.zip
5. Download RUU_Vox_HTC_WWE_1.34.405.1_220.127.116.11_03.10.90_Ship.exe . This is the new firmware from HTC.
6. Right-click the RUU_Vox_HTC_WWE_1.34.405.1_18.104.22.168_03.10.90_Ship.exe and select extract to here using Winzip. The files should now unpack. Verify that there is a file called RUU_signed.nbh
7. Unzip Vox USPL- CID BYPASS.zip and start uspl_116_jockyw.bat
8. Follow the instructions until you see: now start a MTTY session or use RUU to flash any ROM message.
9. Unzip Vox-USPL-RUU.zip and run ROMUpdateUtility.exe. Click on Next twice. The application will now check your phone. Click on the Update button. Verify that you want to update the rom version:
from: image version 1.xx.xx.xx (could be anything)
to: image version vox-USPL