I changed the oil on my 2004 Honda Rancher 4 wheeler today, if you have the owners manual it shows you starting on page 143. If not buy an oil filter from Honda it is about $14.00. Beware it is just the filter no housing. Under the engine the oil drain plug takes a 11/16 ratchet. Drain the oil. Now move to the right side of the bike. 1/2 inch ratchet remove the oil filter bolt. The oil filter cover pulls off, does not need to be twisted. Some more oil will drain beware. Replace the filter and reconnect. The owners manual gives torque requirements for the bolts.
Oil filter bolt torque 13 lbf-ft
Oil drain plug 18lbf-ft
Oil filter bolt torque 13 lbf-ft
Oil drain plug 18lbf-ft