For those of you who’ve never installed a custom ROM on Android smartphones before, here’s a step-by-step tutorial on how to install custom ROM using TWRP Recovery.
Step 1. Reboot into TWRP Recovery.
Step 2. Choose “Wipe”. This will erase all of your settings, apps, and app data but will not erase contents of your internal storage such as personal photos, video, etc…etc…
You should have also used Titanium Backup app to backup all of your apps, which will allow you to easily restore all of you apps + app data after installing a new custom ROM.
Swipe to wipe your data partition.
Step 3. Choose “Install” from main menu.
Step 4. Choose “Storage”.
Then choose the storage where your ROM zip file is located. For me, I am using a USB OTG Flash Drive so I chose “USB-OTG”.
If you downloaded the ROM file straight on your phone, it’s probably under “Download” folder in your internal storage.
Step 5. Browse your storage and find the ROM zip file then Swipe to install ROM.
Step 6. You can reboot system now.
*Note – On AOSP ROMs, you may have to install Gapps zip file to get Google Play Store. If that’s the case, install Gapps zip file like you did with the ROM (without wiping) then reboot.