I have an oil leak.  Oil is dripping off the outside of the road draft tube.  It seems to be coming from around the base of the filter.  I'm not sure how to remove the filter.
There appears to be a hold down bolt (?) on top of the filter but I can't turn it by hand and don't want to wreck it by trying some other means ie: slip joint pliers or worse.  

How do I get the filter off and stop the leak??

That bolt holds the "Can" to the Base. It will unscrew allowing access to the Filter. Should unscrew without any problem as its in an oily place.   If You have a drip check the little Tube that goes back into the Engine. Probably plugged up. Clean it out with a piece of Wire or similar. That Tube allows Oil to drain back into the Engine. You can replace the Filter at same Time  if Oil saturated.

  

the can over the filter will be caved in so no pressure on the seal. be sure to corect this, new seal and do not over tighten the capscrew.well you ar into it remove the whole can ahem.the gasket to the block is another source of oil leaks.the who assembly is 1 of henrys failings. But it is repairable if you think like a oil leak. ps the can to block screws ar fhileps. good luck.