The basic method to reroll for both iOS and Android is to reinstall the app.
However, there is a faster method you can reroll by using BlueStacks (Android). The following guide is taken and edited from Reddit so credits to the original author ZettaiUnmeiMokushirk. You can find his original post here.
First you need to install Bluestacks on your computer. It is an Android emulator and will be your platform for rerolling. After you installed Bluestacks, you need to install the Root Browser mobile app on it. It allows you to access your game data later.
2. Getting the game
You can get the game through the QooApp app. Install QooApp on Bluestacks and download Bleach Brave Souls or search for the apk. Alternatively, you can directly download the apk from apkpure.com
If you installed everything, it should look like this.
3. Starting the game
Just like how you would start the game on your phone. Enter a name, play the tutorial. The default controls are running with left mouse click and attacking with the keys z, x and c. You can change the key mapping by clicking on the small keyboard at the bottom. After a few re-rolls, you’ll get used to it.
A small initial download starts and after you completed the tutorial the game download starts. Depending on your connection it will take a while.
Note on the free pull during the tutorial: there are only 4 characters that you can pull from. The best and the only 4* character you can get is Jūshirō Ukitake, followed by the 3* Rukia, Byakuya and Chad in order of usefulness.
Once you get back to the game, you can either grab the 45 Soul Orbs in your mailbox to do one pull or, play stage 3 and you’ll get another 5 Soul Orbs to do 2 pulls. Time to test your luck! Remember, the game currently does not have an evolve system so a 5* start is definitely important!
4. Accessing the files
First exit the game. Don’t just click the homebutton, you need to properly exit the game. A quicker way of exiting is terminating the task in the settings, but don’t clear data.
Now start up Root Browser. It looks confusing at first, but you just need to navigate through the folders. The path you need is: data > data > com.klab.bleach > shared_prefs
You need to scroll down a lot to find the Bleach folder, but in the end it should look like this.
5. Making a new account/Rerolling
Follow this closely! Inside the shared_prefs folder is a file named com.klab.bleach.xml. This is where your account information such as your UserID is stored.
You want to rename that file. Press down the left mouse button until a prompt to rename it shows up. You can rename it whatever you want, but something like com.klab.bleach01.xml or com.klab.bleachAizen.xml marking your best pull is advised. This way you can always go back to that account by just renaming it to the original filename com.klab.bleach.xml again. You can switch around between accounts without having to link it to Facebook. But make sure there is only one original com.klab.bleach.xml in theshared_prefs folder. You can keep the renamed ones in that folder too, but don’t clear data in the task manager.
If you do not wish to keep your accounts, you can just delete the file. However, your account is gone forever if you do this!
Now you’re ready to reroll. Press the home button and open the Bleach app again. It will not start properly due to the missing file. If this happens, press the home button once more and open the app right again without terminating the task. Usually the opening will start playing.
The game is asking you to start over. After that, just complete the tutorial again until you get the 50 jewels for two pulls. If you don’t like what you got, just keep repeating steps 4 and 5 again.
Note: There is no “big download” this time, since you kept the data. However, the initial small downlaod still seems to be there.
Write down the pulls you get. If you get tired of rerolling, you can always go back to an old account by renaming the preferred file tocom.klab.bleach.xml again. Of course you can also go beyond the first 50 jewels to scout for more pulls.