You need to use GooTool's advanced menu to decrypt the files, which you'll find in [world of goo]\res\levels\[level name]\

I ment the xml file that sets the OCD and other things.

You need to create one called "addin.xml" in this format:

http://goofans.com/developers/addin-file-format/manifest-file

There's an example at the bottom.

But how i create it?

P.S.Please make my GooFans Team member.

You need to right click -> new -> text file (something like that) and rename the .txt to .xml

It worked.But when i try to upload my level it did'nt upload.what can i do.

P.S.There is error when uploading.