How to change the asteroids in space shooter game for mobile?

Hi all, i am new to Unity as well for game development and i am trying to change the asteroids in space shooter game plz help me for the same.

I’m not sure exactly what game you’re referring to so this is just a shot in the dark but…

If it is a 2D game you’re working on then the asteroids will probably be composed of sprites which are just flat images that move around your screen. If that’s the case you simply import a new sprite into your scene and find your asteroids (assuming they are a PreFab?) and replace the current sprite image with your desired one and BOOM new looking asteroids.

Perhaps THIS video will be helpful to you.