Change Stage Background Mid-Fight?

[chocotaco]

Hi everyone. I'm trying to make a stage hack that utilizes a transforming background. Basically, I want the background to be a certain texture, then after a while it would switch out for another texture. I'm sure there's some way to do this, but I have tried everything I could think of with no luck. I have the initial background working currently, but I still need to figure out how to make it switch to the other one. Thanks in advance!