How to change world in Alice 2.2

I started a snow world in alice and did a program. Now, i decided to change theme and want to change to space world. How do I change the world, without losing the code I already wrote in current world?

[DensetsuNoKaboom]

1) Create a new world with the space theme.
2) Right click on the space ground and click "save object". Save it wherever you want.
3) Go to your snow world.
4) Click on File. Select Import and import the space ground you saved.
5) Right click on the space ground, select "methods...", "move to", and make it move to the snow ground.
6) Delete the snow ground, if there are any references to it in the world, change them to refer to the space ground.

Thanks!