Change a SKSpriteNode Image
This method is actually re-creating the the mover object.
mover = [SKSpriteNode spriteNodeWithTexture:explodeTexture1];
You just need to update the texture with:
mover.texture = explodeTexture1;
Swift version:
mover.texture = SKTexture.textureWithImageNamed("explode")
Swift version 3.0:
mover.texture = SKTexture(imageNamed: "explode")
You have to change the texture property of your mover object.
Something like this:
mover.texture = [SKTexture textureWithImageNamed:@"explode"];