To install a custom ROM on a Realme device, follow these steps:
1. Unlock the bootloader of your Realme device. You can follow the official Realme guide for unlocking the bootloader
2. Install a custom recovery such as TWRP. You can find the TWRP recovery for your device on the TWRP official website or on XDA Developers.
3. Download the custom ROM for your Realme device from a trusted source such as XDA Developers or official forums.
4. Transfer the custom ROM ZIP file to your Realme device.
5. Install a custom recovery such as TWRP. You can find the TWRP recovery for your device on the TWRP official website or on XDA Developers.
6. In TWRP, select "Wipe" and then "Format Data". This will erase all data on your device, so make sure to backup any important data beforehand.
7. Go back to the main menu in TWRP and select "Install". Find the custom ROM ZIP file you transferred to your device, select it, and swipe to confirm the installation.
8. Once the installation is complete, reboot your device and enjoy your new custom ROM!
Note: Installing a custom ROM is an advanced process and can potentially brick your device if not done correctly. Make sure to research and follow a trusted guide for your specific Realme device