If you have bootloader 4.6 you cannot do this. Please do not try!!!!
First make sure you have the iClarified Source added to Installer. If you haven't done this already you can follow this tutorial:
How to Add the iClarified Source to Installer
Press to launch Settings from the Springboard.
Press to select General from the list of Settings.
Press to select Auto-Lock from the General Menu.
Press to select Never from the Auto-Lock Menu.
To return to the Springboard press the Home button. Now press to launch Installer from the Springboard.
Press to select the Install tab at the bottom of the screen.
Press to select iClarified from the list of categories.
Press to select Baseband Updater (04.03.13_G) from the list of Packages.
Press to select the Install button at the top right of the screen.
Press to select the large Install button that appears.
You will receive notice that process will take about 10 minutes. Press the large OK button.
THANKS****: A big thanks to Viper who stayed up till God knows when helping me out with this! Oh, and bricked his phone testing stuff for me lol. (Which btw he managed to miraculously recover). Note: you shouldn't have any problems as long as the procedure isn't interrupted!