1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 219Get this manual
FILTER REPLACEMENT Remove oil reservoir (rom pu mp adaptor If oil is cleanretain it in clea con tai ner Use pliers and remove filters (a) by pulling fi lter upward and rOla ling filt er back and for thas shown
Push new fille rs on oil inlel ubes, hand tigh then place I" socke over filter and lap each fille on lightas shown