Step 1. First of all download and install adb driver in PC.

Step 2. Download the Rom which you want to install on your android mobile.

Step 3. Open the folder where your Rom zip file is placed.

Step 4. Press and hold shift button, right click and select open command window/ Power shell here.

Step 5. Now boot your mobile into Recovery mode, then select advance then ADB sideload and then swipe to flash.

Step 8. After installing your in your mobile screen it will shows ADB sideload complete Successful, now click on Reboot system and remove your data cable from PC.