[General Topics] _OldSalt_:
Warning: Even an expert runs the risk of “bricking,” or locking up their Android device when modifying it. Often this is a ‘soft brick’ from which they can recover, but sometimes the device is “hard bricked” from which no recovery is possible, and the device becomes a source of spare parts. Proceed at your own risk. Neither the author, nor XDA is liable if you do “brick” your device.

Note: I have insufficient posts to include outside links. I'll add them when I do. Until then you'll need to search the 'net.

Keeping that in mind, you may wish to acquire an older model device to practice with before attempting to modify leading edge devices. Kijiji and Craig’s List are good sources for low cost, used devices that can be used for practice. I acquired the Samsung Galaxy S5 neo (SM-G903W) with Android 7.0.0 (Nougat) installed, I’m using in this guide for about $20 USD. Although any device will do, try to get one from the same manufacturer as the device you want to modify. If your device is a phone, you do not need a SIM card to follow this guide.

The Android OS is a derivative of Linux, and many, but not all commands are the same. You should refer to Linux or Unix manuals for an explanation of the commands. Search the ‘net for “Linux Commands” to find the latest manuals.

As the boot animation and sound are the most common modifications, changes to those are the goals of this guide. It seems as though there is an app for everything now. Yes, they are handy, but this guide will use the command line for many of the modifications. I use Terminal Emulator on the device for command line access. I also use BusyBox to expand the command set available. Both are available from the Play Store. You need root access to install and use BusyBox.

The first step is to read the manual for your device. Pay particular attention to the method used to enter the download and recovery modes. The Samsung Galaxy S5 neo uses volume up + home + power to enter the recovery mode, and volume down + home + power To enter the download mode from the power off condition. Press the volume and home buttons first, and then press the power button while holding them down. The device will boot into the desired mode. You may also require special USB drivers on your PC for your device.

Next you need to take as complete a backup of your device as possible using the stock options. See your manual for help with this. It’s also a very good idea to download the full firmware, as well as the boot and recovery partitions and any tools needed to re-flash this software. The best way to find these is to consult the manufacturer’s website, then this forum, followed by a ‘net search if nothing else provides results. For my device I need Odin on my PC. I found the full firmware at sammobile.com and firmware.mobi. The boot and recovery images can be extracted from the Samsung file, and then re-compressed using 7-zip on your PC. The firmware.mobi website offers all three files for several versions of Android, as well as a configured Odin package to root my device.

Now that we’re ready, the next few posts in this thread will cover the following sequence:

1. Root Device

2. Install Recovery

3. Install Applications

4. NANDroid backup

5. Make your modifications​