Some people say you could just boot into fail-safe mode, and you'd be
able to rename the directory. I haven't tried it, so I wouldn't know. To
be honest, I havn't tried this method at all, it's all theory for now.
But it sounds like a plan.

I've been through this little hoop/exercise in the "olden days". Before I
was smarter (grin). Bottom line... forget it. You'll have ton more problems
than being short of disk space. Just cure the space issue and move on.

-Frank