NSIDis

Good morning.

I would try to decompile an NSIS file, to learn how it is written and organized...
I would read the original .nsi script.

I've found this link:

http://nsis.sourceforge.net/Can_I_decompile_an_existing_installer

I've downloaded "NullsoftDecompiler or NSIDis".
After extracted, I noticed missing tutorials.

I'm not expert. Can anyone teach me how to use it?

Thanks.