[Upgrading, Modifying and Unlocking] flinx1:
Thanks go to goroh_kun, ayati and DoomLord. All the usual warnings about attempting to root a phone apply. This works on a phone with build number V16R24C, which is current as of this writing. I can't speak for any later updates.

You will need the following:

Java SDK (required for android dev kit – get the JDK): http://www.oracle.com/technetwork/java/javase/downloads/index.html

ADK: http://developer.android.com/sdk/index.html

ADB driver: http://spf.fmworld.net/oss/usb_driver/f-05d/index.html

F-05D rooting files: http://ayati.cocolog-nifty.com/blog/files/F05Droot.zip

zergRush files (tested with v4): http://xdaforums.com/showthread.php?t=1319653

Optional:

-	a terminal application of your choice

-	busybox installer from the market

-	English versions of the .bat files (remove the .txt extension): http://pastebin.com/RBCWvzES and http://pastebin.com/EQfjpDAM

Part 1, installing the ADB driver:

1.	Install the JDK

2.	Install the ADK

3.	Go to C:\Users\YourUsername\.android and edit the adb_usb.ini file.

4.	Add 0x04C5 on a separate line at the bottom. Save and close the file.

5.	Reboot the computer or restart adb

6.	On the phone, press home, settings, applications – toggle Unknown sources to On.

7.	Same place, press development and toggle USB debugging to On.

8.	Connect the phone to the PC, and when prompted, navigate to the location where you extracted the ADB driver.

Part 2, rooting the phone:

1.	Extract the zergRush and rooting files to the same folder. (put the English versions in the same spot if want to use them instead).

2.	With the phone connected and in debug mode, run the f05dsu.bat file (DO NOT RIGHT CLICK AND SELECT RUN AS ADMIN).

3.	You first will get asked to go to Settings, Setting my body, Step/activity counter app, Pedometer use, is turned On. Press space after doing that.

4.	You will then get asked to toggle the same setting OFF once, then back to ON. After doing that, press space and the phone will reboot

5.	Wait for the phone to reboot and connect over USB properly. Press space when ready.

6.	Files will be transferred over and the phone rooted. If you don't get any errors, press space and wait for the phone to reboot again.

7.	The phone should now be rebooted, and you can install Busybox and Superuser from the market.

I had trouble getting the Busybox installers to work properly at first – the stericson one would wipe su and require re-running the f05dsu.bat, and the jrummy one would simply not start properly. I suggest trying the jrummy16 installer first just to see if it runs. In the end I had to do things manually to get it installed, but once that was done both installers worked fine.

Part 3, optional, installing Busybox manually:

1.	If superuser has been lost, re-root the phone.

2.	Open up your favorite terminal application and enter the following manually:

su
soff
mount -o rw,remount /system /system
dd if=/data/local/busybox of=/system/xbin/busybox
chown root.shell /system/xbin/busybox
chmod 04755 /system/xbin/busybox
/system/xbin/busybox --install -s /system/xbin
dd if=/data/local/su of=/system/xbin/su
chown root.root /system/xbin/su
chmod 06755 /system/xbin/su
echo insmod /data/local/lsm_disabler.ko > /system/xbin/soff
chmod 755 /system/xbin/soff

At this point you should be able to do a "which su" and get /system/xbin/su as a response. If you don't get any response, Busybox is not properly installed (start over). Doing a "ls -ls /system/xbin/su" should also NOT return a symbolic link to Busybox – if it does, you'll need to copy over su from /data/local again. The same goes for soff. Once this is done, start up jrummy's Busybox installer to confirm the installed version of Busybox, and upgrade it if you want.