[Sony Ericsson Xperia Mini, Mini Pro, Xperia Pro, A] [W]ar[H]ead:
YOU ARE DOING IT AT YOUR OWN RISK!​

Simple method to root ICS 4.0.4 (4.1.B.0.587 & 4.1.B.0.431) without downgrade to GB. :)

Works on LOCKED/UNLOCKED bootloader.

1. Before you start:

Go to:

Settings -> Security > Mark "Unknown sources"

Settings -> Developer options -> Mark "USB debugging"

Settings -> Xperia > Connectivity -> USB connection mode > Select "MSC mode"

2. Download and install Flashtool -> Click!

3. Download the respective 4.1.A.0.562 kernel to flash:

Arc/Arc S:

[url=http://www.4shared.com/file/qNTvdPI6/Lt18i_41A0562_Kernel.html]Arc/Arc S 4.1.A.0.562[/url]

Ray:

[url=http://www.4shared.com/file/QSM6uqPU/ST18i_41A0562_kernel.html]Ray 4.1.A.0.562[/url]

Neo/Neo V:

[url=http://www.4shared.com/file/yte1KEDs/MT11i_41A0562_Kernel.html]Neo/Neo V 4.1.A.0.562[/url]

LwW, Mini:

[url=http://www.4shared.com/file/QSM6uqPU/ST18i_41A0562_kernel.html]LwW, Mini 4.1.A.0.562[/url]

All other users:

[url=http://www.4shared.com/file/yte1KEDs/MT11i_41A0562_Kernel.html]All other users[/url] or try the kernels for Arc S and Ray

4. Go to folder where you have Flashtool -> firmwares -> and put the kernel here.

5. Run Flashtool and click on the flashing icon.

Select "Flashmode" -> ok

If you have setup like on the picutre - press OK

6. Follow the steps and flash.

Flashtool may show error after flashing kernel, no worries. Even your build number, android version won't change. Everything would remain same. So please don't go to phone settings to check anything

7. After flashing restart your device, It may not start completely, may remain at Sony logo or blank/black.

Whatever the status is, just restart your device and proceed with the next step.

8. Connect your mobile to PC and root -> http://xdaforums.com/showthread.php?t=1601038

9. Now download kernel you have before root:

If you are on 4.1.B.0.431 - download kernel for 4.1.B.0.431

If you are on 4.1.B.0.587 - download kernel for 4.1.B.0.587

[B]Arc S[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/qUi1JFQI/Lt18i_41B0431_Kernel.html[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/1UAuDS2T/LT18i_41B0587_Kernel.html[/url]

[B]Arc[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/G9D3aawP/LT15i_41B0431_kernel.html[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/G9D3aawP/LT15i_41B0431_kernel.html[/url]

[B]Ray[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/kyWH-JbP/ST18i_41B0431_kernel.html[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/UkWY6V8K/ST18i_41B0587_Kernel.html[/url]

[B]Neo[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/gECp47SN/MT15_41B0431_kernel.html[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/cKuZ59bd/Mt15_41B0587_Kernel.html?refurl=d1url[/url]

[B]Neo V[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/hHJpD98a/MT11i_41B0431_kernel.html[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/jPW_lhLx/Mt11_41B0587_Kernel.html?refurl=d1url[/url]

[B]Mini[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/WZIBZ9og/ST15i_41B0431_Kernel.html[/url]
4.1.B.0.587 - Not found

[B]Pro[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/I7OvtE7m/XPERIA_PRO_MK16i_431_STOCK_KER.html[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/Qewv_kjw/MK16_41B0587_Kernel.html?refurl=d1url[/url]

[B]Live with Walkman[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/WWOMPIFs/Wt19_41B0431_Kernel.html?refurl=d1url[/url]
4.1.B.0.587 - [url]http://www.4shared.com/file/bWVyFhcE/WT19_41B0587_Kernel.html[/url]

[B]Active[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/wkbgw1M9/St17_Xperia_Active___41B0431_K.html[/url]
4.1.B.0.587 - Not found

[B]Mini Pro[/B]
4.1.B.0.431 - [url]http://www.4shared.com/file/Fl2VL0EX/SK17_41B0431_Kernel.html[/url]
4.1.B.0.587 - Not found

10. Now flash downloaded kernel using Flashtool

Enjoy! :D

This tutorial is based on THIS THREAD