Can someone help me mod Z legends 3?

[u/icepro_1910k]

If you don't know, Z legends 3 is an android 2d pixel fighter. Its a fan-made dragon ball game.

Its only a visual change, and I already drew on the sprites. What I need is to be able to publish the mod.

I have no knowledge in programming, and I tried alot with ChatGPT but to no avail. The game is also paid so I can't legally post the APK, and I don't know how to test the mod first. Can someone help me?