I have never taken the tire off to change the filter on my 2001 250 (same crankcase as the 300) and see no reason to do so. The filter cover is easy to reach, even on the ground (I use an ATV jack, an item you my get for you ATV). Whenever you work on something for the first time you need to pay close attention. A shop manual never hurts either (there's an accessory you can buy, TROX90). I use to oil the foam outer filter only until I upgrade the filter to a foam filter with the prefilter, now I oil both.