The last time I replaced the oil filter, I left the oil-filter cap on
the fluted end of the filter. Now, the oil-filter cap just spins on the
filter. I've gotten the cap off but the fluted "corners" of the filter
have been rounded off so I don't think I can use a new cap. How can I
unscrew the filter? Is there another tool that I can use to grab onto
the filter?