Oh some knucklehead did a quality write up on r&r-ing those many moons ago... 
 
Not plastic but terrible design and quality regardless.  
Skip step 1 as it is the only way to get in there.  BUT not necessary to fix properly... and BTW do all six while there as I can assure you all will need done sooner rather than later...  ounce of prevention so to speak...
Good luck and happy nutserting 
