The readme says something about putting something in "valve/models", which means there must be a folder named 'valve', in which there must be a folder named 'models', in that folder is where you dump the files as directed per the readme.
I've already said that I don't have "models" folder in the half-life directory. In valve folder there is SAVE and some folder that has NOTHING to do with models/sounds...
Oh, also I recommend to read the whole thread before writting something.
No, we were all lying in order to make you type in all caps and replace exclamation marks with the number one. But now that you have discovered our little plan it is best for us to come clean and tell you all about our devious little plan.
Also, just checked, it's 'valve' not 'hl' in the Steam version.
How the folder structure can look.
If you don't have 'models' where I have it, just create a folder there with the same name.
All the default files are in the gcf files, they're archives containing all content, so you don't overwrite anything when you install custom stuff. Did you unpack the zip/rar? Was there a folder structure inside the zip/rar?