Jeep: 95 grand jeep cherokee 4.0 liter, two vibrations, oil filter housing

Question
I have two question.. First.. I need to change the three o rings in the oil filter housing.. My hayns manual has nothing on this.. The flat bolt that holds this housing on is a star 60.. I have applied a great deal of tourque trying to get this bolt loose, it will not budge.. Does the filter need to be removed and then remove the hollow bolt that the filter screws on first.. Second question... Chasing down a vibration at 40 and 65 mph.. After three new joints and a balance job on the shat from the best shop in the area.. I still have the vibration.. I took the shaft out and the vibration is gone..I turned it 180 and it gets worse.. what do I need to look at?  If I may add one more question.. My engine code says my o2 sensor is malfunctioning.. The light does not come on till the exhaust gets to 600 degrees.. then light comes on.. ok heres the question if I replace the 02 sensor will the code light stay of or will I have to take it to the dealer to remove the code?  Thanks for your help  

Answer
Your first question, I don't know, I have never had to take one off.  When I have a question like that, I usually visit my local Jeep service department and ask one of the techs for an opinion.  
Number two, vibrations are illusive and sometimes impossible to track down.  Again, take your Jeep to a driveline shop, have them put it up on a hoist, run the Jeep at the speed you feel the vibration and have one of the mechanics look it over as you do.
The code should reset when the 02 sensor is replaced, if that is the problem.