I managed to scratch the manual shift knob top-cover-indicator after wearing a ring on my right hand, and now the plastic chrome covering is chipping off. It's kind of annoying and I'd like to know my options for replacement.

Can I just replace the chromed top cover or do I have to replace the whole leather assembly?

How do I get it off -- it doesn't seem to simply be threaded on.

Where can I get a new knob at the best price?