If you are looking for the decompiler itself, visit https://github.com/jindrapetrik/jpexs-decompiler
List of issues
: The issue tracker is now writable again and logged users can download files too. But note that our support is very LIMITED.
#1580 Editing Import Assets
How do I change the URL in ImportAssets2 to load a swf file from a different url?
You should find the ImportAssets2 in the others section. Then press edit under the right tree. And you should be able to change the importasset URLs there.