Does anyone know how hard it would be to convert the Lunar Lander game to use OpenGL to draw the graphics instead of Canvas and onDraw methods?

My game I created is based off of the Lunar Lander demo but my graphics aren't all the smooth so I was hoping to implement OpenGL. I just wanted to know do I need to do it from scratch or can I just change bits and pieces?

I have no idea how to use OpenGL and all the tutorials I find are about 3d, not 2d.... Any help is greatly appreciated!