Is the 4th step under " Create the Skin DLL" here correct?
Yes, it is correct. The Rhino SDK samples on GitHub has a skin sample if you need to review.
The line says:
(TargetPath)" "$(TargetDir)$(ProjectName).rhs" Erase "$(TargetPath)"
It looks like it is missing a matching quotation mark and possibly the ‘copy’ command?
Thanks - I’ve updated the guide.