Install custom Android version on a foreign phone

Installing Play Store and other Google Apps requires functionality not give to ordinary use apps thus these apps need to be installed in the system partition.

However, the system partition is inaccessible to unmodified phones without root (admin) permissions. Also installing Play Store requires to perform some modifications to the system which cannot be done when Android is running (regardless of Android version). Thus these tasks are done by a special mode known as the recovery mode. The default recovery mode shipped with the phones are designed to prevent modifications to the system and thus the Android Modding community has created custom versions like (CWM, TWRP, Philz, etc).

First you need to configure you computer to connect to you phone via ADB (Android Debug Bridge).

Download ADB and Fastboot drivers (Windows | Mac) and install it on your computer. This will also install the drivers.

Then you need to install a custom recovery:

1. Download TWRP recovery for your device here.


2. On your device, go into Settings -> About and find the Build Number and tap on it 7 times to enable developer settings. Press back and go into Developer Options and enable USB debugging.


3. From your computer, open a command prompt in the folder you specified when installing the drivers and type: adb devices. You should see an entry like: <Sl. No.> device.
   Note that you might see a prompt on your phone asking for permission, if so, accept it.


4. Type: adb reboot bootloader. Your phone will switch on and will be in the fastboot mode.


5. Your device needs to be unlocked before it can flash custom images. To unlock your device type: fastboot oem unlock.


6. Rename the file you downloaded in Step 1 to twrp.img and copy it to the folder you specified when installing the drivers and then type fastboot flash recovery twrp.img followed by fastboot reboot.

Now to install Play Store:

1. Download Google Apps from here after selecting ARM64, 6.0.1 and pico (I assume you are on the stock ROM).


2. Store it on your phone in an easily accessible location and type: adb reboot recovery on your computer.


3. Let the recovery start and when presented with the options press Install.


4. Navigate to the location where you save the file in Step 2, select it, and swipe across the slider to confirm.


5. After it is done press Wipe Dalvik cache followed by Reboot System.

That's all you need for Play Store.