I'm sorry, I know this has to be something simple but I've checked the manpages, the mount, the permissions ... (edit: combined history into one sequence as requested. Starting to seem a not-simple ...
I understand the reasoning why nearly every unix version doesn't allow hard-linking of directories (in fact HFS+ on OS X is the only one I know, but even that isn't made easy to do yourself). However, ...
Having a (single, no batch filesystem processing needed) symlink, what a command line to use to turn it into a hard link to the same file?