Though an official Android 4.4.2 KitKat update for the Sony Xperia Z1 is reportedly just around the corner, there’s no doubt many users not interested in waiting. Fortunately, XDA member Daddye has dropped an unofficial version of SlimKat ROM that’ll have you running the latest and greatest in no time.
This guide will walk you though the installation process for SlimKat 4.4.2 on the Sony Xperia Z1. As always, Androidstray assumes no liability for the firmware installation. Proceed with caution.
Before Getting Started
Do not use this guide for any device other than the Sony Xperia Z1. Flashing this ROM onto any other device will most probably result in a bricked phone.
You must have your Sony Xperia Z1 rooted, with a recovery utility like ClockworkMod installed. As always, you want to backup your device and charge it to at least 80 percent.
Finally, enable USB Debugging mode by navigating to Settings -> Developer Options.
Updating Sony Xperia Z1 to Android KitKat 4.4.2 via SlimKat ROM
1) Download the Android 4.4.2 KitKat SlimKat ROM, Fastboot, as well as the Google Apps package, which can be found here, here and here. Extract the ROM package to get the “boot.img” file.
2) Using your USB cable, connect your Sony Xperia Z1 to your computer.
3) Create a folder on your phone’s SD card named Fastboot and copy the Fastboot files there.
4) Copy SlimKat custom ROM and the Google Apps package to the root folder of your handset’s SD card.
5) Turn off your phone. While holding the Volume Up button, reconnect the phone to your computer and wait until the LED turns blue.
6) Navigate to boot.img file and open a command prompt by holding shift, right-click and selecting “open command prompt.”
7) Type “fastboot flash boot boot.img” into the command prompt, followed by “fastboot reboot.”
8) Once the violet LED activates, immediately tap Volume Up to enter Recovery mode.
9) Perform a factory reset.
10) In CWM recovery, navigate to “Install Zip from SD card” and select the ROM file copied earlier. Repeat the same step to install the Google Apps package.
11) In CWM recovery, tap “Reboot system now” to restart your phone. This may take some time.
12) After restarting, your Sony Xperia Z1 will officially be running Android 4.4.2 KitKat SlimKat ROM. Kudos.