Dump the exe you have now to install litestep and download the newer version in the downloads section of this site.
I think its 3.0.2 or newer by now.
Its OTS2 and a lot more easier for new users.
Just make sure you download OTS2 themes from this site.
Download the zip to your desktop and rename it from .zip to .lsz and double click...
If you have support for OTS2 forget the first part.