I do all my own Winterizing.
1. You can buy all the good oil. I changed over to synthetic, easier cold starts and nice for the trolling motor
2. You save a few buck's, no waiting and you get better the more you do it.
3. You get to know your engine. So when crap happens you know where to start
If you can always start you engine once in the driveway. First of the year there are always the people trying to figure out why there engine won't start at the dock.