It's time to get it ready to go for the spring and I need to do the following: Change the impeller, prop seal, fuel filter, l/u oil. The local shop with certified mercury mechanics wants $150-200 to do the above. I know I can change the l/u oil and fuel filter but how hard is it to change the impeller and fuel filter on the motor. Would it be worth it to do it myself or have the pro's do it.