Android Firmware Modification

Hi, I have an Android-based remote controller, i want to customize its OS and also boot animations, etc.

This is the firmware in which we need modifications:
https://enordpvtltd913-my.sharepoint.com/:f:/g/personal/ros_enord_tech/Ej-at5yiHfJOr1VFN3_2J1wBT5bgkjy8QHmZ68rF4cKI4Q?e=AJQdoH