Please follow the instructions from Paul's thread here. You can also find the Smartflash tool and the drivers overthere.
To use P990 flash to flash this baseband:
- Download the utility file from Paul's thread.
- Download the driver file from Paul's thread.
- Download the baseband file below
- Run the SmartFlashTool_P990.exe application on your PC
- Turn device off, remove battery, plug device in while holding volume down - you should see a software update message on screen and the COM port should be filled automatically in the flash application below after installing the drivers if required.
- Select the 'ROM Copy D/L' tab
- Ensure 'Normal Mode' is selected
- Ensure 'Erase CAL' is NOT selected
- Click the browse button next to 'CP Bin:' and select the baseband (FLS) file
- Click 'Start' and wait for the flash to complete
Download the 0725 baseband from v20m here (multiupload). RIL for v20m is here.
PLEASE MAKE SURE YOU UNDERSTAND YOU DO THIS AT YOUR OWN RISK, AND I AM NOT RESPONSIBLE FOR ANY DAMAGE TO YOUR DEVICE.